That's some scary shit! I've never seen that in my life. It's hard to imagine that piece of framing is really supporting anything with three nails in the OSB! Having said that I would do two things: 1. Use a circular saw to cut out enough of the OSB to observe the Pex and make any repairs 2. Call an engineer/contractor/building inspector to look at that abomination and tell you if it's actually supporting anything.