Factual error: A ham radio requires the person to hold down the button while talking. Numerous times in the movie they are talking without pushing the button.
Suggested correction: This is actually subtly addressed in the film. The magic which allows the radio to work across time also allows the two men to speak without pressing the button. There is a moment where Frank wonders what is going on with the radio and presses the button a few times to talk but then notices that he doesn't have to press the button to be heard.
If that was true, then it wouldn't make sense for them to continue to show Frank and John hitting the squawk bar throughout the film.
That is a separate issue. The mistake entry states that you need to hold the button to talk on a ham radio, which is true, but the magic ham radio in the film doesn't require it. If the actors continue to occasionally press the button that could be considered a character mistake but it could also simply be a force of habit by the characters.
