User blog comment:Zack Tan/Volume 7 Intermission/@comment-33177490-20150907185855/@comment-130.180.74.86-20150911135531

Maybe the two player found out (or they just believed that because they were out of options) that you have to die to get back to the real world. Because of that he killed his comrade and didnt wanted to be resurrected.

But that is just a mere thought.