The technicality is that it wasn't an add-on rating; it was the ATP certificate ride itself. So he might have needed the extra hours; he might not have needed the extra hours; the extra hours might have made no difference to the overall totals. They didn't know - "it is far from clear on this record whether he would have had the 1500 hours total flight time needed to qualify for an ATP certificate check-ride unless the 123 falsified hours (210 minus 87) were counted." That's the kind of technicality where the tribunal itself speculates a bit and manages to over-complicate things also.
For me, the takeaways of the case has always been:
"...more importantly, even if respondent had only needed 25 hours in the Westwind, the false statements as to his flight time would still be material..."
The reasoning, "...there was no way for the examiner to tell from the records tendered how many genuine hours he actually had..." is also a takeaway because it tells me how important it is to log things that you want to log for the memory but not count (like the half hour you were sole manipulator your friend's multi when you are only ASEL) to log it in a way that makes clear it is not being counted.