Left 4 Dead 2 (Xbox 360) Easter Egg - Dead Rising Refrence

When you have downloaded the new campaign "The Passing" you can view an easter egg referring to Dead Rising.
On the second level in the campaign you will reach a room where you must go up some stairs to proceed with the level.
Before you do you may notice that the rooms downstairs are covered with graffiti. Just to the left of a "REPENT THE END IS NIGH" graffiti tag is a tag saying: "Otis, ran out of film, helicopter not coming, zombies too fast, won't get out alive, Frank West."
On the hugely succesful 360 game Dead Rising you play as Frank West, a photographer stuck in a zombie apocalypse. This makes out that this was written by him as it states he ran out of film (for the camera), helicopter not coming (on Dead Rising you escape via helicopter), zombies were too fast (on Dead Rising the zombies are classic slow ones, so Frank isn't used to fast ones) and he writes the messege to Otis, who is the janitor from the shopping mall where Dead Rising takes place.