If you ran it long enough, there would be damage on all of the lobes.
Stock cams have indeed gone flat, sometimes in just a few miles. Performance cams have lasted a long time as well. There doesn't seem to be a consistent pattern, except that your odds are worse with current oil formulations and better with the older-style ones. Performance cams with big lobes and high spring pressures also seem to worsen your odds, but that seems reasonable if you're moving the lifters more and pushing them into the cam harder. And again, it's not universal.
LN Engineering has a nice FAQ. The question of metal-to-metal contact is addressed here:
https://www.lnengineering.com/oil.html#Z3 The whole page is worth a read if you want to know about the whole zinc-level thing.
--DD