yeah, this would be bad. It is from too much pressure in the blood vessels in the lung. It can be fatal but, obviously when the meth and symptoms are gone, the problem is very likely to be gone too. It is highly likely to get worse with repeated doses, so, he cannot take any more. Meth is a stimulant and raises pressures in all the vessels. Surprisingly, stroke, heart attack, local problems with other organs are much more common than lung pressure problems. He might have some other condition such as not much lung (severe lung disease) or abnormal circulation (an otherwise small heart valve problem) that caused this to occur with the meth. This would have to be quite a bit of other problem, so a simple physical with the doctor being told to look at causes of increased lung pressures will likely find it. An echocardiogram can find all those problems and directly measure lung pressures.