If I were in that position, I would have done research and posted details in the answers. "I checked my log files, and received an average of X visitors over December, which compares to Y visitors over November. I also noticed IP Address K was crawling my site daily and I can't determine who they are, so I blocked their access. Perhaps that was the source of the abuse."
A little effort might have gone farther. Or who knows, maybe it would have had no effect.
pretty obviously if he had replied yes to any of those it would mean he had been able to find out what caused adsense to disable his account.