Alberta Case Proves that the Due Diligence Defence Can Actually Work


The Insider spends a lot of time explaining the due diligence defence and how you can use it to avoid liability for safety violations. However, in most safety prosecutions, this defence fails—just look at the results from each year’s Due Diligence Scorecard. But before you conclude that that we’ve been pulling your leg all this time about the value of due diligence, here’s a recent case from Alberta in which a company successfully argued that it had exercised due diligence. This case is a good reminder to companies in all jurisdictions that due diligence is a viable defence.  Here’s a look at the case and why this company succeeded where so many others have failed.


What Happened: An oil company hired a crane company to lift a piece of oilfield equipment and an independent supervisor to coordinate the work of employees from several companies and supervise the lift. The crane operator and a rigger, who were employed by the crane company, set up the crane for the lift, which involved raising and connecting a “grasshopper” linkage to the “doghouse” of an oilfield drilling structure. Two oil company workers secured the grasshopper’s yoke pin to the doghouse. But they didn’t secure it with a safety pin. After the lift was complete, the rigger was removing the sling when it got caught on the grasshopper. The rigger stepped on the lower section of the grasshopper to free the sling. The grasshopper came down, striking the rigger in the head and killing him. The crane company was charged with two OHS violations for failing to ensure the health and safety of the rigger.

What the Court Decided: The Alberta Provincial Court acquitted the crane company on both charges, ruling that it had exercised due diligence.

How the Court Justified the Decision: The court said that the incident happened because the grasshopper wasn’t secured with a safety pin. It was the responsibility of the oil company workers to insert that pin. The grasshopper appeared to be secure although it wasn’t. The crane operator and rigger didn’t know that the safety pin hadn’t been engaged and they couldn’t see whether it had been installed. So they relied on directions from the supervisor, with whom they’d worked before without incident. But although it was ultimately the supervisor’s responsibility to ensure that the safety pin was in place, he also was unaware that it was missing. In addition, no one involved in the lift knew that the rigger was going to step on the grasshopper—it was a spontaneous action in response to the stuck sling. The court concluded that this tragedy was “one of the bizarre and unimaginable accidents that are rare.” So it ruled that the crane company had taken all reasonable, practicable steps under the circumstances to ensure the rigger’s safety [R. v. Procrane Inc., [2011] ABPC 28, Jan. 26, 2011].


When a safety incident occurs, the first instinct is to blame the company. Although this reaction is understandable, it’s not always fair. The due diligence defence is intended to ensure that companies get a chance to prove their innocence and aren’t automatically held liable simply because an incident has occurred.

But due diligence has become very hard to prove. In recent years, only a few companies and individuals have actually been able to use the defence successfully to avoid liability in an OHS prosecution. So why did the company in Procrane succeed when so many others have failed? The court described the company’s safety program as “exemplary” and fully supported by the company’s president. It also listed the various facts that supported the company’s due diligence defence:

  • The crane operator and rigger were experienced workers who’d worked with both the oil company and supervisor before without any safety issues;
  • The crane company had a safety manual and a safety training program;
  • The crane operator and rigger had attended all relevant safety training as well as the safety meeting for the lift;
  • The rigger was wearing a safety helmet at the time of the incident;
  • The crane used for the lift was appropriate for the job; and
  • The crane company had performed all required hazard assessments before the lift.

So although it would be easy to conclude that the due diligence defence only works in theory and never in practice, the Procrane case should provide solid reaffirmation that maintaining an effective safety program will help your company minimize the risk of liability under OHS laws.