This piercing was a fairly crude DIY piercing (pictures of the procedure on his IAM page) and the jewelry is definitely longer than needed, plus there is a random o-ring on it which I can’t figure out, yet here it is looking ok at 4 months old.
No piercings on the hand are a particularly good idea because of the use and abuse that a hand gets on a daily basis. However, transfinger piercings have a fairly remarkable chance of healing if the subject leads a fairly gentle life. Obviously, for the best chance of getting any piercing to heal, you should seek out an experienced piercer who uses proper jewelry and has an understanding of why something may or may not work out. Nonetheless, once in a while some “crazy kid” does a DIY piercing that shouldn’t last more than a week and yet for some reason it does.