Gold Is Where You Leave It - S1-E19
Revealing mistake: Buck lights the fuse and tosses the dynamite-filled barrel at the bad guys. We see the explosion. Unfortunately, after that, we can also see the intact barrel still rolling away in the dirt.
A. B. and C. - S1-E3
Revealing mistake: In the fight at the end of the B scenario, Number 6 has a small problem. His pants split open in the back. Fortunately, they somehow manage to mend themselves again.
Revealing mistake: As Delta Tango 19 takes off from the airport, there is a shot where it is actually landing. This can be seen from the fact that there is no runway behind them, as it is in front of them.
Revealing mistake: In the boiler room fight scene between Wilk and Gilman, the stuntman for actor Don Gordon (Gilman) is obvious by sporting more hair than he should have.