How much did Logitech pay for this article?
No, seriously, if you do a google search for "logitech doubleclick" you'll find hundreds, if not thousands, of people complaining about practically all of their mice doubleclicking; either new out of box, or a few months down the line.
There is a massive design flaw with their mice that are 10m+ click rated (typically 50m), because they use D2F-C switches instead of regular D2F Japanese switches. The C means Chinese, they rated for more clicks, yet have far lower tolerances and suffer issues, even right out of the factory.
RMAing your mice can do nothing. Buying a new one can do nothing. This affects the cheapest mice from $20, or the most expensive up to $150 designed for "pro gamers". Last I checked, pro gamers can't have their mice multi-clicking, as it could cost them thousands of $$$ at a tournament.
I've personally owned a G900, 4 G903's, and a PRO Wireless. All $150 mice. All multi-click. Both the regular and side buttons (but typically regular). And the G90x all have scroll wheel wobble issues to varying degrees. My G900 lasted the longest (about a year), and it was the lowest rated clicks one. Half of my 903's doubleclicked within the first week.
The only workaround is to buy replacement D2F switches and resolder them yourself; something not many people want or even know how to do.