It's a massive stretch to say he was heavily invovled in all 3 goals. First goal he wasn't involved in at all being in the box vaguely nearby is not being heavily involved. Second goal he's taken out on the halfway line having a city player pick up his touch past Rose before being flattened isn't being heavily involved, he's still recovering from the terrible challenge when the ball goes in the net a good half a dozen passes later. And the third goal, he initilly carries it well before grinding to a halt in the box when he should be committing the defender, the ball goes back and is recycled before Bernardo does what Grealish should have, attacks the box and scores. Being overly generous he's had a small involvement in one goal, definitely not heavy involvement in all 3.