A good example here of working as a team to address foul play.
As you view the clip, the referee is following the ball and is not in a good position to clearly see the incident of foul play as it was late, well after the ball had gone.
The Lead Assistant Referee however is perfectly placed and as required of the AR's his focus is not the ball but for incidents just like this. As soon as the foul play occurs, it is not a matter of simply radioing in the call but visually to put out the flag as he does. This indicates to coaches, players and supporters that this has been seen and the referee team can deal with it, just as they do here.
As Assistant Referee's we have an important role to play and not simply be another set of eyes on the ball. Work your positioning just as you would as a referee and obtain the best angle depending on if you're lead or trial AR. This will make sure that as a team you're all best placed to get clear views enabling you to capture incidents including foul play & points scoring situations.