Ameobi actually closes down hard, did in the last game but completely ran out of steam in the second half then as well. Cabella is new to the league, country and team, Arfa offered nothing more after years in the team. Likewise Cabella was trying to offer that something special in a team that when he joined was playing dire football. Maybe he'll be good, maybe not, but it's a bit early to judge him.
Ref should give this penalty to Everton, while he did get the ball, a little, he got the player first AND didn't actually get the ball away from the player. There is a difference in reality and the rules, if you tap the ball but it basically doesn't move and the opposition player is still able to run onto it and score then it's still a foul even though you get the ball.