It could also be worth pointing out to him that although survival probabilities are useful measures when applied to large or even moderately-sized populations, they aren't necessarily that useful in trying to predict the outcome of a single event. "90% probability of survival" didn't mean that your friend was going to live, and "35% chance of survival" doesn't mean that he is going to die. What is certain, however, is that he is not done yet.
It could also be worth pointing out to him that although survival probabilities are useful measures when applied to large or even moderately-sized populations, they aren't necessarily that useful in trying to predict the outcome of a single event. "90% probability of survival" didn't mean that your friend was going to live, and "35% chance of survival" doesn't mean that he is going to die. What is certain, however, is that he is not done yet.