I haven't seen it mentioned whether Roy knew Henry before the robbery? If not, and assuming the 2nd assailant was indeed Roy's cousin, then it stands to reason that Roy got intel from him. Which makes the cousin more than an accomplice. If Henry wasn't flashy, then it was known he had items worth stealing at home (golf clubs, etc.) And I realize a gun changes the dynamic, but if all the roommates had been home, there'd be 4 grown men (including a football player) that could have made this, at the very least, more complicated and not clean. So, I think Henry was being watched and the assailants knew his schedule and when he'd be alone.
We're told Roy used threats...it's entirely possible the cousin was made to help kill (and/or dispose of) Henry or he'd be next. And even without murder the cousin is up for aggravated assault, robbery, false imprisonment, felony possession of a firearm, IN commitment of felony etc. etc. If he actually said it, Roy was correct this would be "messing up" life. It's curious that if the 2nd man was a cousin, his immediate family wasn't tracked down and questioned? Or mentioned by Henry's either now or then?
I think it's possible Henry DID go under the radar thinking he'd keep his family safe. Just not permanently. I can see a scenario where he'd hide until the arraignment (2 days?) was over, thinking that would appease Roy and show he wasn't going to pursue it. But Roy and/or cousin got to him first. I think Roy is likely directly involved in the killing part to be sure it was complete, since he was the first one charged.
So where do you go that is no where near your family or another friend? I find it unlikely he remained in the apartment, and I'd imagine his roommates would have similar concerns unless everyone was packing. He might have gone to a hotel to lie low, possibly one with a 24 hr office and selected a room right next to it for (attempted) safety. I'd also like to know who else knew the predicament he was in...MSU staff? If he was really freaked and desperate, I can see hiding in a locked, concrete equipment room for 2 days. But a hotel seems more likely if he wasn't afraid for his life, just more assault.
And if he was still reasonably functional, what other commitments did he have those 2 days... a regular appointment, practice, study group, habit of going to the movies alone? We know he was pistol-whipped once (haven't seen if he was rendered unconscious), and could certainly have been again. We already know Roy used bindings (and probably a gag the 2nd time). Incapacitated but not bleeding out would make less of a mess in a car trunk until they arrive at wherever he is killed and disposed of. I'd imagine that location wasn't just a roadside ditch, but had more thought put into it.
Who is the 2nd man, what happened to him in the days after the disappearance, and where the hell is he now?