This hand is from a tournament at a local cardroom, blinds are 300/600, stack sizes are:

UTG-3000
UTG+1-3900
UTG+2-15000
UTG+3-approximately 10-15k

Player 1 goes all in for 3000, player 2 goes all in for 3900, player 3 tries to go all in for 15,000 but is told he can't because the last action was less than a full raise, that he can only call or fold, so he calls the 3900, then player 4 also calls the 3900, but says after the hand that they would have folded to an all in. Player 4 winds up flopping 2 pair and winning the pot, even though they wouldn't have been in the hand had player 3 been allowed to reraise. Was this the correct ruling or should player 3 have been allowed to reraise preflop?

Obviously player 3 can go all in and the dealer is an idiot. This rule only applies to people that made a bet or flatted and a raise did not open the action back up. For example:

Player 1 bets 100, player 2 calls 100, player 3 goes all in for 175, player 4 calls $175, player 1 or 2 cannot go all in because the bet $100/called $100 and faced an incomplete raise. Player 4 could have raised all day.

Players should have called floor. I don't know a ton about tournament dealer rules, but I would doubt that after player 3 just called that they would have any recourse for the dealer's error. But this error is pretty egregious.

Standard protect your hand scenario.

Dealers are not perfect. This particular problem keeps coming up. Often the Dealer will change their position once its explained to them. The best way to explain it is to ask the dealer whether UTG+2 would have been allowed to raise if UTG+1 had folded. Another way to get the message across is to remind the Dealer that only UTG would be forced to just call if everyone else folded or called. And finally I will say to to the dealer that for players who haven't acted yet on any given street they always have the right to fold, call, or raise when facing one or more bets.

A lot of the time the Dealer will still insist that nobody can raise and I will 100% of the time call the Floor over if I am in the hand and the Dealer's opinion has never been upheld.

Any time a Dealer tries to impose a rule that I don't believe is correct I will call the Floor over if I am in the hand. If I am not in the hand I will correct the Dealer out loud but often that isn't enough. In that case in a cash game I don't call the Floor but suggest to the players in the hand that they should. There have been times where the Floor was not called and the horrible ruling stood. In a tournament though I have to call the Floor because the outcome of the hand affects me and all the players at the table and in the tournament.

What the hell that's complete bogus why isn't that player allowed to ISO with his stack? Rick covered everything there.

Player 4 obviously had a pocket pair between 5's and 9's, no way he makes that statement with AQ+ or better.

I personally would be all over not being able to ship it as player 3, the last action wasn't a full raise? So what? The UTG player shipped, so now at this point any bet made after him has to either compensate 5-6BB's or fold, it's not that hard.

Must have been some table talk after this one.