Revealing mistake: When Iris is sitting in bed recording the message for Barry, she is holding her iPhone so that the start button is on the left side, but the "video record" button appears on the right. Additionally, her right hand covers the speaker area of the phone fully, including the front facing camera. It is impossible for Iris to be recording the video live and reveals that the video footage was recorded ahead of time. The illusion that the video is being recorded by Iris live is further ruined by the fact that the room lighting is turned off in the scene, but the recording is well lit.
Continuity mistake: The explanation that Cisco draws about the endless cycle changes in between shots, not counting the added words "past", present", and "future" (which he could have written when off camera, not that it would make sense to do so since he already explained what was past, present, and future). Where the loop crosses itself is higher up as well as the "FF + TR" being different.