I saw a link to this review on another post, but avoided coming here until I'd watched the episode. You've captured the flavour of this one well, and I'm glad I didn't read it before I had watched it!!
I find it interesting that had the mother taken responsibility for the child wandering away form the park in the first place, that none of this would have been necessary. The embedded commentary on blame shifting that society is so adept at doing today is quite apparent also. There are quite a few themes running through this episode.
Thanks for your review.
RE: Black Mirror Season 4 Reviews: Episode 2 - Arkangel