Detergent Contamination of Processed Foods
Food processing plants have strict regulation to comply with, which means washing the equipment often. Most places wash the machines with detergent at the end of the shift or batch. 

It may be quite possible for the detergent to get stuck in places or not rinsed perfectly and next batch of food picking it up.  Their main goal is to not get caught with bacterial infections.  Seems that you were the unlucky buyer of the first pieces of jerky coming out after a wash.

I'm not aware of published statistics for soap in food, and it is also less of a liability for them even though soap can be carcinogenic.  This kind of stuff is not rare by any means.  You decide if an anonymous base wage factory worker is where you'd like to place your trust when it comes to food you eat.