I don't think this is correct. I stopped refereeing about five years ago, so I am happy to be corrected on this - but, it is only handball if it is deemed deliberate anywhere on the field of play, i.e. accidental handball is not an offence. Deliberate generally extends to having hands out, in the air etc. and not necessarily just the intent to handle the ball. So for example, if a player has his hands across his chest, and it hits his hand - it shouldn't be given as handball regardless of the situation in the game.
With regards to the red card - quite rightly, it should only be given if a goal (or an "obvious goalscoring opportunity") has been denied. The referee made the decision assuming the shot was on target. As replays have since shown that the shot was going wide, a goal has not been denied and a penalty should be awarded for deliberate handball with no further action required - as there wouldn't be anywhere else on the field if the ball was going out of play. A player can be cautioned if he "breaks up play" or otherwise with a handball, the same way he would be if he had committed a foul in the same situation. So there may be an argument for a yellow card, but only if the referee had thought the ball was going to hit the post and rebound out for example.
So as I say, unless something has changed, which it could have - I have vastly cooled my relationship with football in all regards - I often question where the notion of a caution for deliberate handball originated from. It is a particularly popular assertion among pundits, notably Souness. I do agree though that situations like this highlight the need for clarity where the referees judgement of goal scoring opportunity or not is the difference between a penalty and a red card, or just a penalty. It is the same judgement that is made when assessing whether to give a red card for denying an "obvious goalscoring opportunity" through a trip or push - or as I like to call it, the "last man" fallacy. Pundits; Souness, again.