Presumably they think this is a defense that will hold up in court as plausible deniability if they are ever sued for defamation relating to this comment.
In the hypothetical scenario that this commenter is implying that Solaris contains (or contained) a load of IP which is non-clean-roomed Linux copyright (is that the implication??), then the current owners of Solaris would be the ones getting in trouble with - the FSF? That would be Oracle.
