Okay.
The rules state that "If the challengee does not make a submission, they will have been considered as declining." This would lose them 5 points.
However. The challengee did indeed submit submissions, and there's no clause in the rules that allow the challenger to decline their own challenge. JCJ's analogies are a little odd but they make the point.
As such, I'm going to roll with MMC here and give AB an automatic win on those challenges. AB gains 8 points, FHM loses 8. The remaining challenges will be voted on normally. Do provide any disagreements or comments here!