Fremmer, I read wildlife biologists' claims that a deer's attention span is around twenty minutes. After that, if a deer isn't further disturbed, life returns to normal.
I once had a very patient and cooperative buck remain unconcerned through eight misses. He was just a wee tad further away than I'd thought; about 150 yards further than my guesstimated 400. The muzzle blast of an '06 just didn't bother him at all. I finally figured out my own problem, slow learner that I was.
His mistake was coming 100 yards closer, and stopping at a time that the breeze settled.
Other times, I've vibrated off of an easy shot or two, with an ensuing amount of gritching and foul language directed at the dumb SOB who couldn't deal with the problem at hand...
, Art