If the same thing happened in the original example, but the turn card was not out yet, should it still be dead?
I have had this happen twice in the last week where a player let substantial acction take place after him without speaking up, but the dealer had not put the next card out. Both times I warned the player but gave him the option to call, but not raise since all the action was otherwise complete. (And in actuality, both cases were pre-flop with the flop not dealt yet, but I believe that shouldn't make a difference.)
To be clear on my stance, I 100% agree with it being a dead hand if the next card had been dealt afterwards though.