I think the hit caused it, but it wouldn’t have caused it without the vaccine-induced myocarditis.
My guess is, because of the vaccine, it was going to happen at some point within weeks. Being at the game accelerated it, luckily for him, because he received care immediately.
I wonder where his mother/family stands on the vaxx....I would love to see them demand further tests, etc. I don’t even think the doctors are saying they are 100% sure it was “commotio cordis”.