Just the start of it all

Apparently the end of American Life on Mars is drastically different somehow to the British version? Only I cannot find anyone actually saying what it was in ways I can understand. I would quite like to know, but I basically have no intention of ever watching it. Can anyone take two seconds to explain it to a bear of very little brain such as myself? Thx.

(With luck, there will be spoilers in the comments.)

Probably everyone knows this already, because I'm very late to the party on this particular comic, but there's a bit in the first (Jaime Reyes) Blue Beetle trade (I forget the exact issue number) where Jaime's having come back One! Year! Later! is now edging out boy-who's-been-in-a-coma for school corridor excitement factor ...

... and so coma-boy starts telling everyone that when he was in his coma, he found himself back in 1973 as a cop.

I squeed.

So I've been thinking (instead of sleeping, mostly) and ...

( Cut for spoilers, tl;dr-ness, and an image )