Aside from the zombie apocalypse being in progress with most of the population being killed, along with the enormous amount of walkers he'd have to contend with in the streets once he did escape the roof.
So yes, they never said he was dead. It was a good assumption.
only if he can't get the handcuffs off (which of course is very tough to do).
I continue to think rooftops are one of the safest places in that world. Walkers can't climb.
I kept calling for them to get to the roof of the petshop on Sunday, especially when it looked like Rick may be coming to save the day with a mobile home.
If you're ever stuck, get yourself on a roof and hope help comes along and/or wait for the walkers to pass.