Can anyone explain how he is alive at the film's end?

Rating: Null/10 (23 November 2006)

It looked to me like he died in the explosion but then he comes walking around the corner like he and the girl had not met, this film is twisting my mind. It just makes no sense to me. When they sent him back in time he seemed to recognize all of the stuff he had left at her house (fingerprints, etc), some kind of parallel existence maybe, explain how you interpreted it. And what became of the crew that was in charge of the device that let him go back in the first place? I enjoyed this movie but it left me hanging with too many questions. It has dogged my mind since I left the theatre and I can only hope the DVD will shed more light on the ending.