I checked, it's not my finger.. anyone from TFP missing a finger lately?
Maybe we should help them out and say it's not us...
Smartassery aside... If it happened at the level of the bean growers, it might be possible that the missing finger belongs to that of an illegal laborer. Maybe it wasn't reported because this person wouldn't want to be discovered.
I would surely hope the processors of the canned beans would have things in place to get rid of large chunks of anything (including rodents or insects) from the end product.