I'm with Mamacita. You clearly have good intentions but you state you really don't know the fellow at a deep level. There are likely a number of factors that he has not shared with you that are influencing his actions and decisions.

I totally get the absolute importance of getting this issue diagnosed and treated by the best in the best facilities but in the end every person has to do what feels right for them. We can advise, educate, influence but not force people to act. Maybe time to cool it for a bit and offer encouragement as you can. don