Doctor here. I’m not sure how pathophysiologically you could design a quick aneurysm creator, since it involves weakening the vessel wall layers. Moreover, you’d have to be sure the aneurysm actually burst to cause symptoms/death. Also, there’s a good chance you live if treated in a timely fashion and if you’re one of the lucky ones where the hemorrhage that ensues from the ruptured aneurysm isn’t massive. So no, I don’t think aneurysm creation is ripe for a quick kill method the way inducing myocardial ischemia (heart attack) is.

This (ruptured aneurysm) is actually a pretty common way young people die when they do, and they usually have no symptoms before it happens.

I’m not denying or endorsing the potential for a cover up here, just saying the purported clinical reasoning fits the picture of the sudden death in an otherwise healthy young person.