I may be way late on this buuuut....

[CitizenSoldier]

I was thinking that too maybe randy wasnone of the infected at the place already and micheal had a runin with him expecting to die made an attempt not to be turned so he tried to kill himself failing to do so resulting in a broken arm

[scbubba]

I hadn't considered the attempted suicide theory with Michael's injury and the Waterworks incident.

My thought was that he was rescued by a non-turned Randy when the others escaped the behemoth in the explosion. In the ensuing attempt to get out of the Waterworks, Michael and Randy get cornered by the biters/behemoth and Michael either leaves Randy for dead or Randy sacrifices himself to give Michael time to get out. This weighs heavily on Michael's conscience since he feels like he failed and/or betrayed Randy.

Just a theory - nothing to back it up....

[Witch_Doctor]

My thought was that he was rescued by a non-turned Randy when the others escaped the behemoth in the explosion. In the ensuing attempt to get out of the Waterworks, Michael and Randy get cornered by the biters/behemoth and Michael either leaves Randy for dead or Randy sacrifices himself to give Michael time to get out. This weighs heavily on Michael's conscience since he feels like he failed and/or betrayed Randy.

Same thoughts here. He seems like something REALLY bothered him at the waterworks. What ever is was, the way he's hesitant to talk about it makes me think it has more to do with shame or regret than the shear horror of the experience.