it's due to an incompatability with the esportal anti-cheat, as they use a third-party. Krimz was playing esportal when he got vac'ed. The same thing happened when valve made a vac ban a while back, can't remember when it was. A lot of people got banned for playing esportal and using the third party ac. It'll get removed.
I'm not sure its ever happened at this level of CS except to people that actually cheated. AFAIK its happened to people in tier 2 who used a unauthorized 3rd party platform to play CS but they got revoked.