Honesty really is the best policy. I was on KLM flight from Amsterdam to Edinburgh yesterday afternoon. The captain announced that there would be a short delay due to a the technical paperwork. 5 minutes later he came out of the cockpit and, over the PA system, explained that a scheduled inspection of he landing gear had been missed and the aircraft could not be flown. He admitted the problem, explained the consequences and advised us of the solution - transfer to another aircraft. Although we were very late departing nobody complained - the captain did the right thing by fessing up and keeping us informed.