Even if his plan was to touch it past the keeper, his touch was way too strong (prior to contact) to catch up to the ball. My point is this just isn't cut or dried either way. This isn't 100% a foul. I could even question if the keeper was actually late for his challenge. The attacker had to leave his feet and arguably create a dangerous play to get off a panicked touch in time. Had the attacker not made this rushed and awkward touch the keeper's timing might of been perfect. Ultimately, both players took a risk, but I'm not sure one bears the burden of the outcome more than the other.
Too be perfectly honest, if my son is the attacker I'm probably adamant its a PK, if my son's a keeper (fortunately he is not) I'm probably just as adamant its a not a PK. However, I can't for the life of me see how this would be a DOGSO and a card, but reasonable minds can disagree.