Character mistake: Once Santino and Ares find John again in the hall of mirrors, John is fighting two of the grunt men that came in with Ares and kills them. Both of which had light assault rifles and weapons on them. John and Ares proceed to empty their pistols out at each other before she runs off with Santino. John then throws his empty pistol away and gets up to pursue his target unarmed and while limping. It is unreasonable to think that someone with his skill and training and experience would not take two seconds to reach down and pick up one of the guns dropped by the two men he just killed before chasing after his target, especially given the highly trained body guard with him accompanying his target. As well as probable encounters with more grunts. To add to this, he was seen doing just this moments before when he had limited ammo and each time he'd down a few enemies he would pick up one of their guns and continue. (01:41:30)
Character mistake: Poirot identifies Prof. Hardman's revolver as a 1927 police-issue weapon due to its blued finish and chequered grips. In fact, these features were common in the widely-available civilian versions of the Colt 'Police Positive' revolver and not the least bit specific to police-issue weapons.
Character mistake: When we see the relative positions Eddie and Johnny have, Eddie appears to be the one that should have done the signaling to the patrol car instead. (00:55:40)
Character mistake: Henry believed his call to the Saratoga County Help Line #1-518-555-0121 was not effective because Glenn's brother George was the Social Services Director. The genius failed to look above the county level and discover there's a STATEWIDE CPS number that he could have turned to #1-800-342-3720. A call to the State CPS hotline probably refers calls to the relevant county, but Henry could have used what he wrote in his notebook "Why Calling Child Protective Services is not a plausible option." (00:28:56 - 01:01:11)
Suggested correction: It isn't clear what number Henry called. He had the county number underlined on the brochure, so I assumed that was the number he called. However, I replayed that part and the person who answered said "Child Protective Services." There was another number above for "National Help Line for Victim Advocacy" 1-800-555-0199, but that's not the National Child Abuse Hotline.