Due diligence, records and working with regulators

Lesson 1 described what the law requires of supervisors. This lesson is about showing that you did it. When something goes wrong on a site, the question that follows is not only what happened but what the people in charge did beforehand to prevent it. A supervisor who took every reasonable precaution, and can show it, is in a very different position from one who meant well but kept no record and did not follow up. The same habits also prevent most incidents in the first place, which is the real point.

What due diligence means

In Canadian OHS law, most offences are strict liability offences. The prosecution does not have to prove that the accused intended to break the law or knew of the hazard. Once it proves that the prohibited act happened, for example that a worker was exposed to a fall without protection, the accused is convicted unless they show, on a balance of probabilities, that they took all reasonable care to prevent it. That defence is due diligence. CON-305 introduced it alongside the criminal negligence duty in section 217.1 of the Criminal Code, which applies to anyone who directs how another person does work. This lesson focuses on what due diligence looks like day to day for a superintendent or foreman.

Courts and regulators look at the same practical questions in both countries.

A day in the records

Due diligence is not a binder assembled after an incident. It is the record of ordinary supervision done every day. Here is what a normal Tuesday on Larkspur Commons leaves behind.

• 6:45. Omar walks the site before the crews arrive and records two findings on the inspection app: a missing toe board on the level 5 east scaffold bay and a pallet of sheathing stacked against a guardrail on level 4. Both are fixed before 7:30, and the corrective actions are closed with photographs.
• 7:00. Each foreman leads a pre-task planning session with their crew and the crew signs the plan. Ridgeline Framing's plan for level 5 lists the leading edge, the open stair shaft and wind gusts as hazards.
• 9:30. Dana sees a framer working at the leading edge with his lanyard clipped to his own harness ring rather than the anchor. He stops him, they talk about it, and Dana records a coaching conversation in his daily log. The framing foreman covers anchor points at the next morning's huddle.
• 13:00. A delivery driver reverses into the laydown area without a spotter. Omar stops the truck, reminds the driver of the site traffic plan and records the near miss.
• 15:30. Priya and Omar review the day's observations and update the corrective action log. One item, a damaged extension cord, is still open because the electrician is replacing it tomorrow; the cord has been tagged out of service.

None of these records took more than a few minutes. Together they show a supervisor who knew the hazards, checked the work, corrected problems, coached and followed up. If a worker had fallen at the stair shaft that afternoon, the investigation would have found a system that was working and a specific failure to examine, rather than an absence of supervision.

Writing records that hold up

Records help only if they are specific, timely and honest. Vague records ('site safe', 'talked to crew') prove very little; records written days later, or changed after an incident, can do more harm than having none. Thornbury's guidance for supervisors is short.

Records should say who, what, where, when and what was done, in plain words, at the time. If a record turns out to be wrong, the right way to correct it is a dated note saying so, not an edit that hides the original. Distances and quantities should be written as they were, for example 2 m from the edge, not 'close'.

Enforcement and fair discipline

Rules that are never enforced are not rules. A site where supervisors walk past unclipped lanyards is telling workers that the rule is optional, and a court will draw the same conclusion. But enforcement does not mean punishment first. Most breaches come from a gap in knowledge, equipment or planning, and are best handled by stopping the work, finding out why and fixing that. Thornbury uses a graduated approach.

Two principles keep enforcement fair. It must be consistent: the same breach gets the same response whether the worker is a favourite foreman's best hand or a new labourer. And the supervisor must look at their own part first. If the anchor points were not installed where the work was, the framer who clipped to his harness was solving a planning problem badly, and the response is to fix the planning. Subcontractor workers are disciplined by their own employers; Thornbury's role is to require the subcontractor to act and, for serious breaches, to remove the worker from the site under the subcontract terms.

When the regulator visits

WorkSafeBC prevention officers inspect construction sites both on a planned basis, guided by the regulator's annual high-risk strategies, and in response to complaints and incidents. Construction falls from elevation have been a focus for years. WorkSafeBC reported in April 2025 that more than 1,000 construction workers were injured in falls from elevation in 2024, about three a day, and that it issued 152 administrative penalties totalling about $1.07 million for fall protection violations that year.

When an inspector arrives on Larkspur Commons, Thornbury's procedure is the same whatever the reason for the visit.

• Greet the inspector, check identification and ask the purpose and scope of the visit.
• Call Dana (or Omar if Dana is away) and Priya; the superintendent accompanies the inspector.
• Invite the subcontractors whose work is involved; their supervisors should be present for their areas.
• Be courteous and truthful. Answer the questions asked; do not guess or speculate, and do not hide or alter anything.
• Take the same photographs and measurements the inspector takes, and note what was said.
• Correct any hazard identified immediately where possible, and record the correction.

At the end of the visit the officer writes an inspection report. It may contain orders requiring the employer to correct contraventions by a date, and may lead to an administrative penalty, which WorkSafeBC sets with reference to the employer's payroll and the seriousness of the violation. A stop-work order can be issued where there is a high risk of serious injury. Orders can be reviewed by WorkSafeBC's Review Division and then appealed to the Workers' Compensation Appeal Tribunal, but they must be complied with in the meantime. Separately, serious cases can be prosecuted in court, and supervisors can be charged as individuals.

The penalties matter, but the bigger costs of a serious incident are the human ones and the disruption: a stopped site, a lost crew, an investigation and a reputation with owners who prequalify contractors on their safety records. The example below estimates penalty exposure only to show how quickly it adds up, not because penalties are the main reason to work safely.

# Illustrative penalty exposure after a fall protection inspection (not WorkSafeBC's actual formula)
payroll = 3_200_000            # assessable payroll for the year, dollars
base_rate = 0.0125             # illustrative share of payroll for a high-risk violation
reductions = {"first violation in 3 years": 0.25, "prompt correction": 0.10}
base = payroll * base_rate
penalty = base
for why, r in reductions.items():
    penalty *= (1 - r)
print(f"base amount {base:,.0f}; after reductions {penalty:,.0f}")
print(f"equivalent to {penalty / (payroll / 2080 / 25):.0f} worker-hours of a 25-person crew's payroll")

base amount 40,000; after reductions 27,000
equivalent to 439 worker-hours of a 25-person crew's payroll

The numbers are illustrative, but the lesson is real: a single serious finding can cost tens of thousands of dollars before any human cost is counted, and administrative penalties are only one of the consequences an employer faces.

Supervisors and the investigation after an incident

After a serious incident, regulators interview supervisors. A supervisor may have their own interests at stake as well as the employer's, and in a serious case may want independent legal advice. Thornbury's guidance is to be truthful, to describe what you know rather than what you assume, to provide the records that exist, and never to create or change a record after the fact. Lesson 8 covers incident reporting and the company's own investigation.