Revealing mistake: The fire Steve made when he "traveled in time" back to the Ice Age was obviously fake (computer-generated). The logs were arranged like a teepee and the "fire" was contained to the inner sides - flames did not spread toward the outer edges. Moreover, the fire was built on top of snow/ice but there was no melting under or around the fire.
Synchronic (2019)
1 revealing mistake
Directed by: Aaron Moorhead, Justin Benson
Starring: Anthony Mackie, Jamie Dornan, Katie Aselton, Ally Ioannides
Continuity mistake: Packets of Synchronic were placed on top of the garbage already in the can and were inconsistent from one shot to another. Also, the amount of crumbled papers under the Synchronic decreased. (It is also interesting that no new garbage was placed in the can on top of the Synchronic packets even though over one day had passed).
Dr. Kermani: Only one more sample to get rid of.