netmeg - 2:59 am on Sep 1, 2011 (gmt 0)
Do your ad blocks only have one ad in them? Or are there three or four? Do you know which ad the user clicked on? Is it not possible that the first ad could be paying $10 but the third ad twenty five cents? Also, do we have any reason to be positive that clicks and earnings are updated simultaneously and always in sync? I don't ever recall Google coming out and saying so, and I have anecdotal examples over the years that would suggest they don't.
I don't really see any reason (or motive) behind thinking it some kind of deliberate manipulation.
There are a lot of factors that go into a click at the exact time it occurs - certain sets of conditions on the advertiser side, on Google's side, and on your site's side. All these things have to be totted up to come up with the value of a click. And even then, sometimes Google has to come back later and adjust.
I understand your curiosity, but I think it's one of those things that you can wear yourself out trying to figure out, and you never will know one way or the other.