Have you tried resetting Safari?
That was my first course of action.
I used my knowledge as a techie, PhD graduate student in Computer Network Engineering at the University of California, and my experience as a networking teacher to rule everything out I could.
If anybody knows that any techie type person has blind spots, it is me. My buddy is a PhD Programming Teacher and CompTIA A+ Computer Hardware department head at his college and even though he knew a ton of stuff, from the Widows 98 days all the way back to assembly language and the mathematics behind computing pre-math co-processors, he didn't know XP and NT and kernel based operating systems so he would bring his machine to me even though I was merely his student.
My weakness is in Applications Programming and yes, there could certainly be an initial bug in Safari itself straight from Apple.
What I am going to do for some time, as I have been, is using Firefox and Opera, as they have been stable so far, avoid known dangerous sites/banner ads, keep up to date on viruses, and then reinstall Safari.
If Safari works rather well and doesn't quit over and over, and, I don't go to questionable sites or open questionable e-mail, then I could be pretty confident that Safari didn't have an inherent bug in its original code.
If I then go back to the site(s) in question, where there are admittedly fans of the magazine 2600-Hacker Quarterly, and Safari dies on me over and over, then I can pretty much peg them and simply not visit them anymore.
I will take advice from anybody, with any level of experience on Safari, because there is far too much to know, from all the possible scenarios of why something goes bad, down to the very code that drives that application.
The days of thinking Macs don't get viruses are gone for me. And only in a relational sense could one say that Macs don't get viruses, when comparing it to a Microsoft Windows operating system.