Dovid Gutnick, Rabbi Kramer’s grandson, was learning a maamor (chassidic discourse) with Rabbi Kramer one Thursdy night and noticed that he was participating with more excitement than usual. When Dovid asked him about the maamer, he explained that he had heard it directly from the previous Lubavitcher Rebbe. At the time, after the maamer had been recited, Rabbi Kramer, being one of the only bochurim present, repeated it for all to hear.
After he was finished, the Rebbe approached him – unbeknown to Rabbi Kramer the Rebbe had been there for the duration of his chazara – and corrected and clarified certain concepts of the maamor.
“Imagine! To chazer a a maamor in front of the Rebbe!” said Rabbi Kramer to his grandson.