It likely is a matchup decision. Bills do this quite a bit...they must feel like someone else is better for the matchup they want.
That was Hamlin's man...didn't you see the WR not even know what to do because he was going to try and block Rhodes and Hamlin literally crashed into him for some reason instead of going to the player getting the ball?
That was a "WTF are you doing play?!?" by Hamlin.
The play should have been stopped for a 2 or 3 yard gain at BEST if Hamlin just played it properly...2 defenders and only 1 blocker.