I liked it a great deal, but...
It falls into the same time loop problems that other time travel films (such as Time Crimes) fall into. At the point where the main character first jumps back, the events that cause him to return are dependent on his subsequent trips. But the contents of those subsequent trips are dependent upon what he learns in the first trip. It's a two way dependency that doesn't really work.
The only way you can possibly solve it is rather complicated. You can argue that the very first time the character jumped back, he actually found a DIFFERENT reason to return- one that we never see. When he came back a second time (15 minutes earlier), he would ultimately come to the reason that the audience gets to see (Cynthia) and determine that this is the new reason for his repeat trips. Then, because of this change, the events of his first jump would be rewritten because the first-jump-him would be reacting to essentially NEW stimuli- the events of the second jump and their impact on the camera crew. This process would continue for each jump until a multitude of timelines had been overwritten. The overwriting would finally stop once Pak stopped going further back in time.
Thoughts?