There are some bad things which can happen to you doing this. This video captures the better of the two worse things. This tear is a lot larger then it looks, once the bleeding stops it usually shows its self to be the size of a peanut. This will now take at least two weeks to heal, during that time i must monitor for infection and of course no more finger lifting.
the really bad outcome is tendon damage. This is a very old and very dangerous type of training and you can inflict serious damage to your hands with just one bad pull. So please be very smart and resposible if you do this.
In reflection, the cause of the tear with that weight was wearing slick basketball style shorts. My hand slippedas soon as started the pull and it allowed me to move out of correct position. Lesson learned.