In all seriousness, guy should probably call the yogurt company and complain. Not only is that probably a part to one of their machines and they would probably be interested in getting it back, but they would probably mail him a gift card to say sorry.
Definitely let the company know so they can audit their production line, there are metal detectors down line that should have caught this so this is a major safety issue if true. I'm sure they will be very happy you told them.
In all seriousness, guy should probably call the yogurt company and complain. Not only is that probably a part to one of their machines and they would probably be interested in getting it back, but they would probably mail him a gift card to say sorry.