I'm begining to think that the tougher the shot, the more likely we pick a spot and make a good clean release. I've had the same thing happen, make a great shot on the tough ones and miss the "chip shots".
I made a mediocre shot on an elk this year (hit back) at about 6 yards! He runs out to 40 and stops with nothing showing but his rear end. I alreay had an arrow on the string knowing another arrow in the animal will help recovery and I pick a spot and shot at the only thing visible (his hind end) and the arrow flys like its on a rail right to the bull. Someone asked me "did you pick a spot on the first shot?" I tell them "yep, it was about 6 foot long and tan".