Episode 264: It Looks Like She's About To Die On The Oregon Trail (S19E10 Pathological)
When a Grandma Sheila dream segues into the case of a girl who has been Munchausen-by-proxied into a severe learning disability, you can guess that we caught a Michael Chernuchin episode.
Eventually, the girl kills her bad mom with a hammer which causes bad Barba to rear his ugly head to intentionally force a mistrial to ensure that this episode was a waste for everyone involved, especially the viewers.