lack of communication from bunney to the centre halves - so instead he got dragged in and left his man unmarked.
bunney has never been in the right position at any point during his time as a left back.
From where I was watching (the ideal place to see this in the second half) it was very clear that McWilliams was RB, Goode RCB, Turnbull LCB but not clear at all who was LB. Bunney just doesn't look comfortable there. He looked left sided midfield most of the time.