That quote is a great piece of PR. The number one reason quoted from that Symantec report was: "Microsoft Windows SMB Remote Code Execution". It also didn't have anything to do with what makes Macs crash, it was a report on vulnerability per plat, it mentioned flash in cross site exploits, not flash by itself. But to this day and for a long time the music keeps playing.

Here is a good analysis of that text that explains a lot on how that statement is great PR but nothing more: http://truegryc.blogspot.pt/2010/05/response-to-thoughts-on-...