Don't let others high expectations bring you down. We all face a jihad within ourselves to keep our faith and seek knowledge soely for the sake of Allah. Did you go there to impress the people of the jamaat or did you go there to benefit from their knowledge?! If for the latter, than just say Alhamdulilah. You intentions were good and inshaAllah you'll be rewarded for it. That leader shouldn't have been leading the jamaat if he is how you he is. The best scholars and leaders wouldn't do that, it's childish. And I think there's a hadith about not embarassing your Muslim brothers/sisters. Especially the ones who are "new Muslims". We're suppose to teach them, encourage them and correct them. Not make fun. Anyways, inshaAllah khair.
