Try this shot instead.
Still shots on this occasion are meaningless. You have to see the video to see the problem.
The refs initial positioning wasn’t great but it also wasn’t the problem. As a ref in the Championsip he should have been aware of the possibility the ball might be played to the player nearest him.
The pass doesn’t come from nowhere, there’s a second or two where it’s obvious where it’s going. Mehlem has every right to move towards where the ref is standing to receive the ball as it offers him more space. Whilst the ball is on its way, the ref first steps forward into the problem before getting out of the way. This stops Mehlem having as much time on the ball and Sunderland capitalise well. It’s the refs movement and awareness of his surroundings I have an issue with and not his initial position.