In fairness, one exploit doesn't really undermine being "ultra reliable"; even OpenBSD has had vulnerabilities. Didn't see any mention of previous exploits and too lazy to dig, but if this is the only hole in living memory then OpenVMS is outperforming Windows, Darwin, Linux, and *BSD. Of course, it could just be that nobody's looking.
Archive with the article subheading saying this affects the "itanic" architecture: http://archive.is/NFSOx
Ouch.
The strongest hold is the one no one tries to break into.