Don't ya just hate it when other kids broke your toys & then tried to hide em ??
In gen-av, the pilot's responsible for inspecting the a/c; when was the last time you saw a heavy pilot do a walk-around ?? They depend on (expect?) the ground-grunts to do that -- as you noted.
If you're describing a location where the leading-edge meets the fuselage, it's not like that would be seen from any window on the a/c. Jetway operator sure isn't looking... New aircrew isn't looking...
Plane likely came in damaged the nite before, in the dark -- nobody looked until daybreak.
Cause: metal-fatigue? FOD strike? Lots of possibilities...
Good thing yours wasn't a pre-dawn departure. ^
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