Thank you for asking the query.

Pons is a very important part of the brain which control many vital functions like respiration, circulation, awareness, sleep, bladder control, eye movements etc.

So damage to the Pons can affect a lot of bodily functions. But the extend of the damage is what determines how many functions will be lost and to what extent. He might had the blood clot which deprived the oxygen to his brain even before the fall. Probably that clot might have caused the fall in the first place. And it’s possible that there was some prolonged period of anoxia (lack of oxygen) following that episode.

Unfortunately even few minutes of lack of blood supply or oxygen to brain can be bad. The brain tissues (in this case the Pons) can suffer varying degrees of damage. The prognosis of your fiancé can only be accurately measures only after doing some physical tests, after an MRI study and observing the patient for 48 hours or more.

I hope your Doctor has done this, and they are the best person to comment on his recovery. But there is always a possibility that recovery might be very difficult in certain cases.

If you have any specific followup questions please feel free to ask via this email itself.
Hope this helps