Is that study a randomized controlled study? Was your friend in the control group or in the experimental group? What was the difference of the outcome in both groups?

It's very rare that everyone in the control group dies and everyone in the experimental group survives. Usually the result is mixed.

The problem is that medical doctors sometime make bad guess about how many years the person will survive. That's one of the reason to have a control group, so the error in the guess compensate.