Yeah, I think he must surely come back as a spirit or something - afterall he was billed as such an important character (in terms of how many times we heard his voice over the walkie etc) and seemed to be the Frieghtie-leader - alas, he was only their version of Mikhail - Comms officer.
The constant switching between times (or rather, perception of time) and his subsequent orifice bleeding and death, is most interesting - We know that he couldn't find a "constant" in the future (or, present shall we say), but what if he found one in the past - would that anchor him in the past and allow him to re-live that time-line, despite dying in the future?
Also, it was interesting I thought, that he was conscious of the fact that he 'couldn't get back' - most interesting...
I'll add more later, still trying to get me head around this beautiful mess.