About 80 or so minutes into the movie when the retirees are all on the yacht, there's a shot of the General on the top deck of the yacht. This shot is flipped; you can tell because the medals on his military uniform are all of a sudden on the jacket's right breast instead of the left.
About 75 or so minutes into the movie, after Dewey talks to the retirees right before sailing out for the fishing contest, when everyone leaves, you can see the cameraman's reflection in the store window.
About 70 or so minutes into the movie, when Dewey's talking to the retirees right before sailing out for the fishing contest, the boom mic dips down into frame for a split second.