Diver0001:
Are you saying that in the US no divemaster has ever been dragged through the system?
R..
No, I'm saying that there is no REPORTED CASE in which a DM has been found liable for an accident when the DM is a MERE BYSTANDER.
When I say that no "reported case" has held a DM liable under the circumstances cited, it means that if the issue of DM liability has been appealed to an appellate court, the appellate court has chosen not to make its ruling "precedential" by publishing it. Precedent is case law that can be cited in future legal proceedings as authoritative statements of the law. The lack of a reported case means (1) the issue has never been raised at the appellate level (meaning that if the issue was raised in the trial court, no one deemed the issue worthy of an appeal or all parties were satisfied that the judge ruled properly; or (2) the appellate court believes that issues are sufficiently addressed in other case law; or (3) the appellate court does not believe its ruling on the issues is sufficiently important to publish.
In a case of first impression, meaning it's the first time such an issue has been presented, appellate courts will usually publish their opinions so as to provide guidance on an issue and to set up the issue for review by the Supreme Court.
If a bystander DM were held liable for injuries caused because he didn't step in and correct improper instructions or standards, that case would be appealed and reported. Why? Because such a decision turns a couple centuries of law on its head. It would be such a perverse diversion from the current state of the law that the DM would almost certainly appeal the issue because that decision would be based upon a pretty clear error of law.
This does not mean that a DM has never been sued. In fact, the Tancredi v. Dive Makai case out of Hawaii involves a DM getting sued (along with the dive shop) for the death of a diver. The lack of cases simply means that no appellate court has ever recognized a common law duty owed by a bystanding DM to any unaffiliated persons.