Revealing mistake: Batwoman gets shot in the alley; the bullets create bad looking CGI sparks each time they hit her suit. When she gets back to the cave and sits down as Luke scolds her, you can see her suit bends and folds at the breastplate all rubber-like, making even more unlikely the fact that bullets would create sparks on impact (for what is worth, in the following episode there's a close-up of a bullet hitting the breastplate of the suit and there is no trace of sparks and not the slightest give from the material). (00:02:00 - 00:03:55)
Revealing mistake: The Wonderland gang henchmen dispose of the Crows' van through fire that causes a nice, clean, completely fake CGI explosion, looking entirely disjointed from the rest of the background. (00:02:00)