On Leverage, the first appearance of FBI agents Taggert and McSweeten in Season 1, Episode 5, The Bank Shot Job, where they briefly show up right at the end after everything's all over. Two episodes later, we're properly introduced to them in The Wedding Job, where they meet Hardison and Parker, who are pretending to be FBI agents, and they strike up a bit of a friendship.
In Season 2, they show up again in "The Fairy Godparents Job", and mention how things have been going well for them since they last saw Hardison and Parker... including the cleanup of The Bank Shot Job. Between that, and the way the ending of The Bank Shot Job works better if we already know who these two FBI guys are, it raises the question, was Season 1 shown out of order? If so, why?