I think that AMS will be in addition to their LGW service, I am told by some friends who work as cabin crew for Phuket....As for what happened who really knows apart from to say that pax do not always make the most reliable witnesses.
There does seem to have been something wrong, because I guess that it is unlikely the flight would have been cancelled/delayed just on the basis of unsubstantiated passenger action. Anybody know who does their engineering in either UAE or Gatwick..I guess the only way to tie this one down will be for someone who has access to the tech log to share its contents with us.