Insane man appeared to be just a plot point "This is how we deal with crazy people in 1973." and a as a sort of freaky parallel thing, Sam, this could be you! I wonder what he thought was going on though? "It's all just a BBC TV show! In the future! I thought it was over, but now they're doing another series! All those people, watching us!"

It's mostly just the 'sticking by people even though (because?) they're hopelessly doomed/insane' thing.

Oh god, now I'm thinking about House-Life on Mars crossovers.