The decision to clip one out wide to an offside Deulofeu rather than play an easier through ball to Lukaku who was going through 1 on 1 after making a great run sums up why he's not yet fulfilled his huge potential, imo. If he sees what's ahead of him, he has the ability to play Lukaku in, Lukaku scores and we go in at half time 1-0 up.
You need more than raw talent to excel at the top level. You need a good footballing brain and a bit of mental strength. He's far from awful in this regard, but he's got to work on it, for me.