On Dec 1st I wrote an in depth article about someone who had just passed away. The focus of the article wasn't the mainstream reasons people liked this person, but the reasons I admired them personally along with a lot of detail not readily available on other sites.
On Dec 8th the article went viral on several platforms, social and search, and traffic to that one page was at roughly 300% that of the entire site average for a day.
At roughly 8pm I got an alert telling me that traffic was well above expectations and, since the article has adsense on it, I checked my adsense dashboard. Sure enough the earnings mirrored the increased traffic.
30 minutes later however, they no longer did. The amount earned and click total had been rolled back and a "error in tracking, not affecting earnings" red message had appeared. This morning the error has cleared but the earnings remain lower than I had personally seen earlier, the clicks and earnings were dropped by roughly 33%.
While bot clicks and the like are probably filtered this was genuine traffic and I find it odd that a rollback occured. I don't get surges like that very often so it's dissapointing to see clicks and earnings removed. My traffic logs don't indicate bot-like traffic, is it normal for the rollback to happen during unexpectedly extreme traffic surges?
Google definitely has systems in place to be on the lookout for increased activity. For example, one of my clients whenever the monthly earnings exceed $xx,xxx.xx the account is reviewed and almost always temporarily for a few days with a tiny violation. So now, we make sure we don't surpass that amount because we'll lose more money being "offline" for 4-5 days.
No one here really knows what & why Google does what it does. Google's systems are very inconsistent, meaning that if what happened on Dec 8th happened again in April you may not lose the clicks/earnings. I would not appeal it either - that just gets the attention of the AdSense quality team which in my experience is not a good conversation to be having unless you are appealing a violation.