Did anybody else think Sammy was joking at first? (spoilers for Unforgiven)

When Sam was convulsing on the floor, I swear I thought he was joking. I know that would have been a terribly cruel joke to play, but I thought he might have done it because Dean was constantly nagging him about not remembering. Although the main reason I thought this is because in the preview Dean said "Are you serious?" And I never heard him say that in the episode. Did I just miss that, or did they cut it? But when they actually cut away to the pit, I couldn't believe it. I was just like, poor Sammy...