fischman mistake?

[mostsmooth]

im only learning the holdem thing, and have never played a tourney, but watching last night, the guy goes all in for 7k and fischman just calls with his AK? i would think if hes gonna call an over the top bet from brunson, he should have gone allin on his own, or at least put a good sized raise in. what was he hoping, everybody else would fold? or maybe somebody puts in a small raise after him that he can call?
im not ragging on fischman (even though i dont like him very much), just seemed an odd place for just a call.