Man Birddog, doesn't that just make you feel horrible when stuff like that happens. And then you're left sitting there just playing it over and over again in your head. UGGH! I'm starting to think that any shot over 45 yards (maybe it should be 50), you have to shoot low since they have time to react to the sound of the bow. I haven't had a problem with 40 yd shots, but you see and hear about it all the time. Maybe if it is still and there is no wind they would react like that, but not so much if it's windy. Sounds like some research is in order to find out what conditions make those bucks react like that.
I'm hoping you text me or something when you see those big bucks start chasing. I might just get a sudden case of Buck-itice and have to skip work.
Enjoy the time out in the field.