I was on TXL to LHR earlier this week when a passenger stood up to collect his possessions before we had fully pulled into gate 22. The pursuer was French (very good too) and did this PA which I quote verbatim, but you need to add an
'Allo, 'Allo accent:
Sit down now, we have not yet arrived, you are very naughty!
The worst announcement I've every heard was at a T5 gate, after snow or something, at a T5 in absolute turmoil, was something like:
British Airways regrets to announce the cancellation on BAnnnn to Paris Charles de Gaulle. Please follow the member of staff to Arrivals, collect your bags and return home. Please arrange your onwards travel by telephoning British Airways - we have a card with the number on it. Do not go to the customer service desks, they will be unable to assist you. British Airways apologises for the inconvenience caused.
It may even have been "You must not go to the customer service desks", they were absolutely clear on that point.
Incidentally I just rang my travel agent, they got me on to another flight later that day, I just stayed airside, then checked in online on the computers in Flounge. I then asked them to re-enter me into T5 since I hadn't passed conformance at this point, but all was well.