Did I "win" a jersey?

 Yesterday I rode the mountain from the steep side.  Near the end of the descent, my jersey suddenly changed to a mostly blue jersey with a black swatch.  I also had some sort of jersey next to my name on the rider list.  What was this?  I am way to slow to have won anything. 

It’s the Epic King of the Mountain Jersey. I am guessing you are on Zpower.

Actually I am using a Powertap wheel.  There must have been a mass internet outage or something to get me that jersey!  There were very few riders on so maybe that explains it.  I was putting out maybe  3W/kg average on the climb.  Not exactly KOM numbers