I am a roofing contractor. Your roofer should not have nailed curled shingles. When the roof goes through a couple more wet dry cycles those shakes will curl again and pull those nails out. It's not the damage to the shakes you have to worry about. It's the felt beneath them. The felt does the waterproofing. The shakes mostly protect the felt. Now you have felt with many nail holes in unprotected areas. Good luck.