Curses, Foiled Again!

Poker can be a cruel game. I was playing a freeroll on Pokerstars a bit ago and called another player's all in move with pocket nines. It turned out he'd all in-ed with 4-7 offsuit, obviously a straight bluff. I'm sure you can guess what happened given the title. Yep, I got busted out when the turn and the river produced a 7 and a 4 respectively, giving him 2 pair. Sometimes even the absolute right move ends up being the wrong one.