Smoking weed, especially at first, raises pulse rate and blood pressure. When you have a weakness in a vessel--a little balloon like an aneurysm--that's not at all a good thing. Smoking raises the risk of rupture, particularly during the initial, vasocontrictive post-smoking period.

Eating weed is likely safer, which is why the others were recommending that. But Dave, who is a man who deals with blood vessels for a living, wondered if it might not still be minimally risky if, say, the eaten weed were a heavy sativa and caused even some slight risk of some vasoconstriction/raised BP at it was first being digested. The problem with street-bought weed is that no one really knows with real accuracy what strain it is, so unless she's grown it herself and knows it to be a wholly relaxing, vaso-dilating indica, he was simply questioning taking that risk at all. It's a legitimate question to raise.