Let's see a picture of the chainrings. Like other posters have mentioned, 1 year doesn't seem long enough to wear a chainring into slipping, even with gross neglect. Even if the FD simply threw the chain to the outside of the big ring before it could mesh, it's still hard to visualize the shin then falling onto the chainring unless the right foot slipped off the pedal to the rear. I guess it could happen, though.