I’d have to watch it again to be sure (I’m blocking it from memory), but it’s common in option run plays to leave the edge defender unblocked. If the edge crashes the QB keeps, and if the edge stays home the QB hands off. The whole point is to create an extra blocker by excluding the edge player from the play without blocking him.
It’s entirely possible, and likely, that he was left unblocked intentionally. If that was the case, Taysom made a poor decision by not handing off.
Edit: I just watched the play. He was intentionally unblocked. (In my opinion)