I can see both sides of the argument that Chick, Van_B and others are having, I'll offer my .02 as I can see it/understand.
I can certainly understand Chick's point about it being a cumulative issue. I can understand Van_B citing science supporting different viewpoints.
If a guy is not having his blood work done, and has no knowledge of things going wrong, that could be the very first step in causing the train wreck. Was Luke having Blood work done? Tom Prince said he never did, but it was the first bit of advice he admitted to giving at seminars. At least that's what he said in his 'net posts.
Was Luke prone to high blood pressure to begin with? Many people the world over have high BP, steroids or not.
Nubain is an opiate, and masks pain. Use steroids, push your body beyond the pain barrier (if you can even feel/distinguish between "good pain" and "bad pain") , and you're asking for trouble.
So you have high blood pressure, which is now pushed higher with AAS use, extreme training, thyroid medication, a reckless sense of ones health and a desire to continue on living the dream....you have what happened to Luke.