In a similar(ish) vein, there was one quite recent Albion player, who recieved their first yellow card in league football, before they'd made a single appearance....
I am KICKING myself half to death, at my failure to spot that BigGully was on this occasion having a HILARIOUS joke, rather than just posting his usual pompous mentalism.
Certain that you are incorrect.
If the substitution is completed, and the first player has left the field of play, there is no way that the player coming ON could be sent off for anything the first player subsequently did.
Good question. Personally I THINK that the substitution is NOT complete until the first player has left the field - so in your scenario, the sub would not be allowed on.