I think you are confusing issues. The small screens is an explanation for why the commentators struggle speaking confidently about some decisions that we sit at home and can see as a clear decision.
As well as the point about handball rules being different for goal scorers and everyone else...
Arm was tucked in close to his body. Probably the right decision.
I believe they have a relative small screen to look at for replays, etc, which probably hampers their ability to see things that appear quite clear on larger screens.
I suspect with this game there is the idea of Vincent Kompany returning, and the potential of 'former player coming back to cost his old team' happening as it often does in football. There was also an opening day match for a newly promoted Burnley v (I think defending champs) Man Utd that...