It started a bit upthread, as follows:
So, lets get the it straight. You did not call him a liar. On the other hand, when you said "The post was probably rightfully deleted because there might have been other posts in the subthread that also broke the rules" you implied quite strongly that he wasn't telling the full truth of the matter. I can see why Nigel took exception, though it was perhaps something of an over-reaction. And then you both escalate.
Interesting, on the subject of the two moderators in question - Nigel is is right that many decent people had many problems with them both - but I put them in different categories. I got to understand how Mako works in the discussions around the impending DPReview closure, and his approach to moderation is honest and consistent. That's not to say that I agree with it at all, but I can understand where he's coming from. Caldwell is another kettle of fish entirely. So far as I can see he moderates for his own aggrandisement, plays to the crowd, and seeks to humiliate his victims in open forum.
Incidentally, it also illustrates why unpaid, overworked moderators are likely sometimes to do a perfunctory job. It took me a while to track this dispute back to the origins and work out what had kicked it off. It strikes me that if people want fastidious and fair moderation they'll need to have a premium paid site.