Factual error: The British Army soldiers are not wearing British Army uniforms or carrying British Army weapons and some of them have beards, which are not permitted to British Army soldiers.
Plot hole: The powerful 'amulet of protection' makes the bullets strike the shooters instead of John. Clearly it works not just against magic and other ethereal threats, but also against physical attacks. So why does he almost get knocked over by a car? True, he isn't seriously injured, but he was thrown to the ground. The amulet should have pulverised that car or bounced it at least two blocks away.
Audio problem: When Ilonka is speaking with her father about going to Brightcliff Hospice, in a shot where the camera is behind her, she says "Lots of foster kids. I mean, kids on their own" and the line appears to sync with her mouth perfectly. But immediately after finishing that line, she starts saying "It's a place for teenagers to transition on their own terms", and her mouth doesn't appear to sync up with the audio at all. (00:12:50)
The Gloaming - S1-E6
Continuity mistake: When we first see the guy in the tunnel, he runs to the left in the first shot. The next time we see him, he runs to the right.