Usage patterns
〈事〉とは無関係だto have nothing to do with ~
This incident has nothing to do with him.
〈事〉と無関係にregardless of ~; independently of ~
Anyone can participate regardless of age.
全く無関係completely unrelated
That story is completely unrelated.
〈人〉とは無関係の〈事〉a matter unrelated to someone
I got caught up in an incident unrelated to him.