There is - and should have been a straight red. But, the FA will only review incidents not seen by the match officials. Here the match officials saw the incident - but did not see it clearly. Ref awarded the free kick showing he saw a foul - but decided it was not worthy of a card. Ref was wrong, but I am pretty sure the FA does not review "wrong" decisions.I'm sure there's something in there about intent... well... kinda sure
Maybe if the ref puts the incident in his match report - claiming he saw a foul by Zlatan, but did not see an elbow thrown - but even then I don't think its reviewable.