Unerring smite

Kruggy and I were logged in for a while. We never fought. We were never even in the same area. All of a sudden, he hit me with an unerring smite. And in a cabal by the way (though that may be fine, if a strike is fine). The helpfile isn't totally clear, but I thought you needed to have fought someone before you could use unerring smite. If so, then it's bugged!