Mike,
Looked at your videos again but they are just too dark to really tell much. Still a nice shot!! :D
I suspect that you are opening your fingers to release the string rather than just allowing the string to flip the fingers out of the way. That technique causes the string to drag on the fingers as it goes, causing a burn feeling before long.
I've said many times that this technique was the hardest for me to learn and took a LOT of practice and concentration before it became more automatic.
I, for one, still find that a glove impedes getting a good "deep hook" because of the tubes of leather that the finger tips must try to bend in order to get the finger tips to point back at your throat rather than at your chin. This VERY SMALL difference puts more tension into the string hand and makes the release more difficult.
It is VERY counter intuitive BUT the farther you can curl your finger tips around the string, the MORE relaxed the muscles of the forearm. Getting "fast" movement out of relaxed muscles is easier than getting "fast" movement out of tensed muscles.
Arne