It's a foul to me. Look, it MIGHT be a dive....but given the push occurred just as the player was leaving his right foot, it meant the push was completely with the attacker's momentum - so doesn't take much force to send him flying. So, penalty.
As for the card - there's too much doubt over whether he would retrieve the ball. At best he has a 50-50 with the keeper. That's not obvious. If it denied him possessing the ball and otherwise he would have gained possession before the keeper, then we might have a case.
But there was still a reasonable chance, IMO, that he would have contested the keeper for the ball. So hence the SPA - or to put it another way, 'non-obvious goalscoring opportunity'. If the attacker had no chance, then it's not SPA. Of course, you may consider it to fit into 'reckless' anyway, especially given how deliberate and unnecessary it is.