It's one of those debates that will go on forever, similar to when Keith Curle and Martin Allen were fired. I agreed with Curle going, but I was furious when Martin Allen was sacked, yet even I'll admit that their situations were quite similar at the time of dismissal. They were both on moderately poor runs of results after previously good runs, and it boils down to individual opinion about whether they would have turned things around or not.
If it was me, I would have allowed Nolan at least two more consecutive defeats before pulling the trigger, and if that hadn't happened, my second test would have been that we must have reached the top half of the table by the end of October. But I can also see the argument that form under Nolan had been poor for 8 months, that we'd had a shocking start to the season, and that you might not have wanted to trust his judgement on more signings leading up to the loan window closing.
As I've said in other threads, the bottom line is that Alan Hardy owns the club and it's his opinion that matters, and so it should be. The club ceased to be run collectively (if it ever was) by supporters in 2009.