If it is a new gun, I would give it the toothpaste treatment whereby you lap the slide to the frame with some OLD white colgate that still has grit in it. You could also use flitz? I have done this to every Kimber I own to include my Gold Combat. The Covert II is a kimpro on kimpro finish, this may indeed do it.
After multiple FTF and FTE, I disassembled the gun, coated the rails and inside of the slide with some cheap white Colgate toothpaste. I then reassemble and run the action back and forth 200 times.
Disassemble, clean repeat.
Disassemble, clean, lubricate, reassemble.
Looking inside, especially if it has a coating or other finish, you will see some very light striations where the coating has been removed. if the coating is on both parts, you should see striations on both parts. My Stainless Pro TLE II had a few shiny / polished spots.
This is a patented process so don't tell anyone else about it.
If it is an older gun, buy a new main spring. Kimber recommends a new spring every 1,000 rds. I buy the Wolf variable power springs and they work well. In fact, I just bought a used Grand Raptor that had the same issues as your friend's pistol. New spring, voila. 500 flawless rds so far, most of those reloads.
"If you let a man keep his dignity, you can kick him in the balls and he'll wash your car"