Definitely not a back pass. I thought it was in real time so I’m not surprised those in the ground got it wrong. The reality is that he was trying to kick it away from goal but mis hit it and it looped into the keeper’s hands. It was actually a brilliant call from the ref.
And what would happen if he called it first time but incorrectly ? He would be crucified. There is very little upside anymore for officials in making swift and decisive decisions. Be careful for what you wished for VAR fans.
Same with all the calls for swift and decisive linesman offside...