It is impossible to confirm that he was solo mining and had such a bad luck that solved zero blocks: in this case NO payouts were produced, so there is NO evidence.

Can you people just stop beating the dead horse?

Please stop asking about "payout address": if there were no payouts, it is 100% irrelevant.

It is obvious that Garr mentioned solo mining only because no evidence can be produced. That is, even if he was honest, he could not produce any evidence.

So again, any further investigation makes no sense. If you believe that "payout address" could reveal something, you're delusional and do not understand how Bitcoin mining works.

Let's focus on one fact we know for sure: due to Garr's negligence, mining equipment was not working for us for about a month. (More accurate time frame was mentioned here.) What do we do in this situation?