Would you apply the exact same standard of punishment to a debacle involving hummus and garbanzo/lima bean mixture?
I would. My daughter used to get a lot of migraines. The doctor didn't want to give her drugs because she was only 8. We started her on an anti-migraine diet, basically avoiding all the major food triggers. The migraines stopped completely that very day. Lima beans are on the "avoid" list, garbanzo beans are not. Had lima beans been a trigger for her, and she ate that hummus, not only would she have gotten a few extra migraines, but she would have thought the diet didn't work at all and quit. It would have caused her many, many more migraines and/or drug side effects over the years. Some people have serious allergies, which can be even worse.
Personally, horse meat wouldn't bother me, but it should be labeled.