Agile Scrum is misunderstood by a large segment of practitioners. Scrum deliberately didn't spell out most of the actions required and that frankly has created quite a pandemonium.
This unclarity of action has created ‘theorists,' who run around with stopwatch in hand, staunchly advocating for so-called ‘assumed’ rules.
In my view, though, Scrum needs to be approached with common sense. A high discipline from the team is unquestionably a mandate. But having said that, exceptions and irregularities are expected when you deal with human beings.