Rory,
"XXIT HAPPENS," I'm betting she dropped just enough after you released that you busted her in the blade. "OUCH," but she'll likely survive if so. You said your shooting 63#, what bow, and what DL, you look pretty tall, I'd guess 28-29" at a minimum, and depending on the bow, you may or may not have sufficient energy for that shot into a blade. I did it shooting 72# on a little deer a couple years ago, but I'm not sure on a BIG MATURE buck, I could. "Head up," and don't let it get you that far down. You're a big part of the reason your little bro got his, I'm sure, so don't let him see you down too low!!!