4 - was actually Johnny Carson interviewing Winnie Palmer on the Tonight Show.
Not so much a d-e, but a huge faux pas, was Raymond Brookes-Ward, the show-jumping commentator at the Int'l Horse of the Year Show doubling up on BBC commentary and the stadium. The Beeb was off air but, unknown to him, the arena system was on.
The Queen Mum came into the show ring to present the rosettes etc for a junior event and RB-W turned to his collague and "announced," "What a bloody awful hat the Queen Mum is wearing this afternoon..."
Red faced he was too but the Queen Mum did see the funny side and wouldn't let him forget his remark.