That's what everyboyd says when they get caught. They didn't know it was banned, they didn't read the label, they didn't know what they were taking, their doctor/trainer/teammate gave it to them, whatever. Romero's big claim here is that the packaging did not indicate that the supplement contained a certain substance. I would think that part should be easy to prove if he still has the packaging. I don't know how he's going to prove the part about the clerks assuring him he wouldn't test positive. Also even if it's true that the clerks assured him that there wasn't a banned substance in there, he has to prove that it was likely that they were intentionally misleading him. That is a problem on multiple levels. 1) They are not considered experts on baseball's banned substance list and so unless he asked them specifically if it contained a certain ingredient, their opinion even if it was wrong is certainly not illegal. 2) They would have to prove that the clerks knew that the banned substance was actually in the product. First, it's unlikely that the clerks knew anything more than the packaging. And even if they did, it would be extremely difficult to prove that they did because you would have to prove how they would have obtained the information in the first place. The case against the manufacturer seems stronger because it's not reasonable for them to not know what's in their own product. I don't know if Romero would have to prove that they left it off intentionally or just that they showed negligence by leaving it off.