After trudging up Leith hill in workout mode at 1.8 w/kg, with a continuous stream of riders shooting past, I somehow was awarded the KOM jersey. I suppose if all those folks that passed me had exited the game, I could conceivably have been the fastest up the hill still in the game… but seems far-fetched. Was I the beneficiary of a lucky glitch? Do I misunderstand what it means to ‘take the KOM jersey’?
Was the ‘Live Results’ menu at the left hand side populated JJ?
I had the same experience on Watopia mountain - I managed to gain both KOM jerseys - I’m pretty sure I hadn’t earned them.
The ‘Live Results’ menu at the left was empty apart from my name - which by default meant I was the 'fastest.
Made for a nice picture though 
Ride On!
Unless the riders passing you started before you or at teh same time they would be faster. If they hit the start of the hill well after you - they could pass you can you could feasibly still win.
Benefit of a glitch