Google Analytics is smarter than we probably give it credit!
Last week, during some testing sessions with GTM I accidentally published a version of the tags with an error in the ecommerce tracking. While the code was on for only a few minutes, 14 transactions went through but with the wrong transaction amount format.
Somehow, they got to Google Analytics as a very big number: probably more money than all the money in the world. I noticed them the second day.
2 days later I was preparing to reverse the transactions when I realized they were removed automatically from the reports.
I guess that proves that there is more than it meets the eye (which is huge anyway). If I ever meet you or any of your colleagues +Nick Mihailovski
beer is on me. :)