If it stays ragged it will keep catching and he might eventually ask for a plaster. You could trim it a little maybe but it will be very tender.
I have much experience in this.
DT2 lost a toe nail last year after I accidentally opened the door on his toe.
DD1 lost all ten finger nails, one after the other, after a serious illness.
It will likely fall off. When the new nail grows, keep a close eye on it that it does not curl in at all. Massage on a little vaseline around the nail (sides and top of the thumb/finger) to encourage the skin to stay soft and not to grow too high around the growing nail.