Many years ago before I got my IA rating, I used to do a thorough "100 hr inspection" on my airplane with my AP rating, then paid an old local guy to come and do the "annual inspection". He had worked as an aircraft mechanic for many years in Alaska prior to moving back down here. He always made a point to give the wings a good shove up and down as he once had an airplane FLY in for service in Alaska and while working on it, he noticed the wings were being held on by some screwdrivers shoved thru the bolt holes instead of the proper bolts/nuts.
It is common practice when initially hanging wings back on a plane to use pin punches or screwdrivers to temporarily hold the wing in place..... apparently someone had done this and never went back to install the bolts.
I have heard of many a wild story about how aviation "gets done" up there.
My wife's first husband (deceased), once tried a roll in a CGS Hawk ultralight and ended up buckling an aluminum tube in the wing. He landed in a wheat field and straightened the tube then gingerly flew it back home at very low airspeed.