I've been mulling this question for a few years, and I've debated the wisdom of posting it on this forum, which is frequented by numerous industry insiders, but I think this happened long enough ago that no one will get in trouble; I won't supply any details about the airline, origin/destination, though.
About 4 years ago, I was on a long haul flight to the USA, and when we were on approach to the destination, I suddenly began vomiting

While in the lavatory, the aircraft landed and taxiied to the gate.
Once at the gate, the flight attendant saw me and said "Oh, I'm sorry, I forgot you were in here". The F/A was very nice, and I was very grateful to her that our landing was not delayed due to my bout of emesis, and she did help me get cleaned up (puking while landing tends to be kinda messy).
Was this a serious breach of regulations?