Johnson's "clarification" appears to have been that he was just pointing at a formal apology made by Keir Starmer on behalf of the organisation which he headed and how that had in no way implied that Starmer had done anything wrong.

The implication being that In saying "I'm Sorry" to the Commons Johnson had in no way expressed any personal penitence of any kind. Or sincerity.

I think most people will already have assumed this.