Should be fine as long as we don't try to do anything.

( it'd be pretty impressive to change the past, sure, but he's pretty sure it leads to some kind of... y'know, those like, time paradoxes. if they changed something here and now, the circumstances that led them here in the first place wouldn't have come to be and all that. besides... )

It's probably less like we're actually in the past, and more like we're seeing it through his perspective. You know how time sort of skipped between the carriage and here, yeah? Kinda like the way you only tend to remember the important bits.