Other mistake: When John is watching the video of Cecilia on her website, the video progress bar we've seen twice makes no sense. The first time we see it, it's moving far too fast for the length of the video. Later, we see it a second time, and it has seemingly reset back to the beginning despite it being the same video, and again, it's moving way too fast.
TedStixon
14th Dec 2023
Saw X (2023)
14th Dec 2023
Saw X (2023)
Other mistake: John would have no reason to ask the CT technician if she had any results. He says "that was a long one," indicating he's had this done before and should know it typically takes around 24-48 hours to get results. (Likely just a line of dialogue added for the benefit of the audience, who may not know.)