Revealing mistake: Cottontail gives Tom a wet Willie. However Tom reacts before Cottontail touches him.
Revealing mistake: After young Donna and Bill are swimming back to the boat after what is meant to be a beautiful ocean swim, Donna climbs up into the boat. In the high shot we can see a line or seam in the floor under the water that gives away it's being shot in a pool.
Revealing mistake: After Robin starts to believe that the Teen Titans are in fact a joke, he gets sad and goes out a hole in the wall saying goodbye to them. He fires his grappling gun up and steps out of the wall. But his arm remains bent as he stands casually in the air to be taken upwards. There is no effect of gravity or any realistic body motion in those moment. As his weight should have had him dangle down with his arm stretched out above him and him swaying like a pendulum. Instead he appears as a stationary action figure in a single pose with his elbow bent as he's taken up.
Revealing mistake: When the bartender recognizes Harold and calls the cartel leader, his phone screen stays on instead of turning black and shows that he's still on the lock screen displaying the time, not actually calling anybody. (00:49:30)
Revealing mistake: Callahan proudly shows to a policeman an issue of the Portland State University "Vanguard", the magazine that is publishing his comic. Looking at the prop, it is instantly suspicious because Callahan's name is all over it like he's a celebrity, and in fact, the article on it is nothing but a copy and paste of Timothy Egan's "Defiantly incorrect" article from The New Yorker celebrating John Callahan's talents in 1992. (01:12:55)
Revealing mistake: When Velma sabotages the science project making it explode into purple goo, you can see that the vial of chemicals she tampered with simply spray around clean liquid, and the purple goo falls from above. (00:23:55)
Revealing mistake: In the opening montage, the article "Rucker Park today - The streetball Mecca" is also the rightmost column of the entirely diff different publication that comes in the following shot. (00:02:25)
Revealing mistake: During the scenes with the cast on the bridge, there are clear traffic directing cones and lights visible in the distance, depending on the angle. This was done to prevent people and traffic from getting onto the closed set.
Suggested correction: Incorrect. They make a point of showing that there are "Bridge Closed" and construction signs on the bridge, and you can even see some construction equipment on the bridge itself. The cones and lights are not there to prevent people from getting onto set... they're part of the set dressing, since the bridge is meant to be closed down for construction in the scene. That's why they chose the bridge as a meetup point... there will be nobody to interfere.
Revealing mistake: Near the end when the orphans are exiting the building in the bus, you can tell they practised the sliding part. There are marks in the roof of the bus from previous takes.