In the above case (with the pharmacist and consumer), assuming the following defenses are available to the pharmacist, which defense should the pharmacist pursue?

Stanley refills his drug prescription at Discount Drugs, where he has been a customer for 10 years. Prior to taking his nightly dosage, he notices the pill appears larger than normal. He phones Discount Drugs and explains his concern. The pharmacist assures Stanley that generic drugs sometimes are larger because of formula fillers, but that the medication dosage in his drug is correct. Stanley takes the drug and never wakes up. The dosage given was five times that which had been prescribed. The container from which the pharmacist filled Stanley's prescription had been mislabeled by the manufacturer