Where did he rub the finish off? I have never heard of and/or experienced the Krystal Kote coming off, but I guess that doesn't mean it's possible. However, the part of the siding where the striping is at is not Krystal Koted. I have rubbed some of that paint off there too (& have had the aluminum shine through), plus I've seen just rain take some off. I've not repainted any of it, so I can't help you for a paint color.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR