As a publicly-traded for-profit entity, their number one goal is to make money. Safety precautions are costly, and their motivation will largely stop after meeting regulations (to the effect that they are enforced). It looks like the divers found some violations, and hopefully Enbridge will fix that.
Regulations are costly for business, but a lack of enforceable regulations can be very costly for the public. Of course, there should be a balance. Here it looks like the public is shouldering a lot of risk on Enbridge's behalf.
Sometimes management can do right by the public, making sure that even unenforced regulations are met. Enbridge's history suggests that they don't have that kind of management.