Ok, so the hit is a little high. Not quite helmet to helmet. To me, it looks like he leads with his shoulder and an attempt at a wrap up, with how his arms are positioned. Not helping the problem, the WR crouches his body right before taking the hit, while Bostic is already in tackle motion. The original tackle motion was likely aimed directly at the mid section, but since the WR lowered himself, probably in hopes of getting his shoulder all the way down, he took the hit in his upper chest.
I still don't see how this is an illegal hit. Definitely not worth 5% of a guy's salary.