Okay, I have some theory. The crazy guy (sorry, don't remember the names) showed a photo where our main guy was friends with red hair guy. Our main guy didn't seem to remember that. So, I think something happened to him that caused his memories be mixed and changed. This could be caused by the reason of our main guy being a culprit and being the one who photoshoped the photos. His guilt got better of him and made him change everything what he remembers.
Okay, I have some theory. The crazy guy (sorry, don't remember the names) showed a photo where our main guy was friends with red hair guy. Our main guy didn't seem to remember that. So, I think something happened to him that caused his memories be mixed and changed. This could be caused by the reason of our main guy being a culprit and being the one who photoshoped the photos. His guilt got better of him and made him change everything what he remembers.