The Last Temptation of Barry Allen, Pt. 2 - S6-E8
Deliberate mistake: There's an awkward moment during Cecile and Kamilla's escape from Bloodwork's minions where Cecile doesn't close the door for several seconds so the cameraman can walk through as they follow them.
Going Rogue - S1-E4
Deliberate mistake: When Capt. Cold is about to shoot Joe in the train station, Eddy "shoots" a pillar next to him to make him run. Eddy then comes from behind the pillar that got shot with no cuts. He would have had to been on the complete opposite side to shoot the pillar where it was hit. (00:32:50)
Suggested correction: I watched the scene several times and nothing indicates the pillar was shot from the left side. It looks like the pillar was shot from behind (which is why there's no hole on the side or front), exactly where Eddie would have been standing.
