Another thought
Since you've only seen 3 hands and him play 1, you also have to account for the possibility that he may have been adjusting to the other player during the hand you saw. After all, you've just sat down so you don't necesarily know the dynamic of the table yet.(unless you've played with the others before or something along those lines)
Still a good chance you're toast, but still not enough to fold, imo.
b
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