My guess at the lawsuit is that object to the type of tuna subway is using. Pink slime can legally be call ground beef although most of us would not consider ground beef. I don't know the basis of the lawsuit but it appear from the one picture that at least that subway pack of tuna is kind of a "tuna fish pink slime" Perhaps tuna parts or bone and cartilage scrapping that we would not generally consider tuna - just a guess but lets see what the lawsuit brings