Ok so now you have got me thinking!
Robert's Rules:
11. Deliberately acting out of turn will not be tolerated. A player who checks out of turn may not bet or raise on the next turn to act. A player who has called out of turn may not change his wager to a raise on the next turn to act. An action or verbal declaration out of turn is binding unless the action to that player is subsequently changed by a bet or raise. If there is an intervening call, an action may be ruled binding.
12. To retain the right to act, a player must stop the action by calling �time� (or an equivalent word). Failure to stop the action before three or more players have acted behind you may cause you to lose the right to act. You cannot forfeit your right to act if any player in front of you has not acted, only if you fail to act when it legally becomes your turn. Therefore, if you wait for someone whose turn comes before you, and three or more players act behind you, this still does not hinder your right to act.
So he has lost his right to act in the situation, I have always said that he looses his rights during the round of betting, so IMO the raise after him although action changing has not lifted his rights again so I would say he can only call the raise to 4000, as this raise has already occurred before he called time, yeh the more I think about this the more I say he is bound during the whole round of betting so he can only keep calling or fold.
I am however not certain, what would happen if for example he called time, called the 500 and then additional player still to act raised then to 4000 total, this would be action changing after he had called time and I am not sure if this would release him to act freely, I would say probably not but I am not sure! Hopefully someone else will chime in with the required technical knowledge on this issue!
Stu