Seagull:
At the end, it seems exactly like a Boeing QC/QA issue. Too much of this airplane has been outsourced, literally and figuratively. I've found boombox radios, flash lights, tools, etc., inside 777 pylons, fuel tanks, and empennages.
Not exactly new. During Lockheed's L-188 fix program (late 50s) misc. non-aeronautical hardware - a vacuum cleaner e.g. - were found in the tanks.
