But wouldn't you a similar worry if there was a defined list of reasons for giving compensation? Such as clogging toilets or other drains to create plumbing problems? The expectation of no compensation is standard and within the cruise contract; anything else is simply good-will for whatever reason it was decided.
I don't see the connection you are trying to draw here. I'm pretty sure
DCL has called muster drills in the past without compensation. Whatever specific circumstances existed in this particular situation does not guarantee compensation in the future if a muster drill may be necessary.