I hate to agree with anything out of Aztlan, but I thought the same thing when I first saw it. His body was supposedly beaten pretty badly. I wondered if the time jump in the film didn't account for them beating and torturing him. That might have been their original intention, to beat him on camera and film it to gain sympathy. He could have died, and they made the use of it by beheading his body. He couldn't have been dead too long, because the blood hadn't coagulated yet.
The only thing that still bothers me, is his jaw and lips seemed to be moving when I first watched it. Then there was no blood spray. Does anyone know how long involuntary spasms continue after death, and what the window is for this and the blood to still flow out after dying?