I think the "no excuse, sir" line still has its time and place. I've used it (or some less formal variation of it) plenty of times in a debrief or such setting, knowing that anything else is just reaching into the excuse matrix treasure box. If a specific explanation was asked, then yes, it is the wrong answer. But for the run of the mill "why did you do a dirty roll at 400 kts with the dumps on over CAG's house?" line of questioning, it is fitting. Much better than "I thought that's how you tried out for the Blues?......"