Terrible situation. Hero loses to AQ and Q9 and ties with 79. The latter 2 hands are likely SB hands. And AQ is too. Re-raising from SB with AQ is not necessarily a good play with a drawing hand OOP.
Because the board is so dangerous, I would have checked the river behind and not bet to re-open the betting.
Why would he re-raise so much? Unless he has the AQ, it is not a good thing to do. With four obvious str8 cards, I think Hero is beat more often than not. The pot-odds are about 1:1. So to call profitably, we must be confident that more than half the time we don't face a better str8 but a set or 2 pairs. I have a hard time justifying the odds
I would lean towards folding. But to be sure, not an easy fold. The mistake in my view was the river value-bet on such dangerous board. In most cases I am faced with difficult decisions, I can later re-trace it back to a previous mistake made in the hand.