Because I didn’t do an in-depth inspection. Just a quick eyeball look on the L-19. I did a more thorough look at the K21 since my ass would be in it. Determined it while it looked rougher than I was used to there was no fiberglass delaminating and was in airworthy condition. I didn’t act as PIC. It’s not my job to inspect or regulate airplanes I don’t do maintenance on.