Subdural hematoma recovery??

I found out yesterday that a friend had fallen off of a roof and suffered a subdural hematoma. I guess the doctors drilled a hole in his skull to drain the blood, and now he is in an induced coma to reduce swelling, and on a ventilator. They said that he should make a full recovery. I know that these things vary drastically from case to case, but could anyone tell me about how long the doctors will keep him in a coma and on the ventilator (as in, a few hours or a few weeks)?? And what will his recovery be like, and how long will he be in the hospital? As I said, I know that you can't really give me a definite answer, but just a ballpark estimate would be great, maybe from past experiences that you've had? I really know very little about the subject, so any knowledge would be nice. Thanks a lot.