All Mumineen should read 53 reasons not to believe Daawedar's Daawedari. You can also listen to the reasons.
In the un-edited version of the video uploaded by the Fatemi Dawat site, at exactly (26:53 to 26:57) Syedna Mohammed Burhanuddin says “Mufaddal Bhai ne Nass nu Taaj“. We can also clearly hear Moula stating “Khuda Barakat Aape” (32.40 – 32.43). This statement of Moula is in response to Shz Qaid Johar Bhaisaheb’s Araz. Although most of the other words are a bit muffled, these statements are very clearly heard. Please view this link for the video:
(The original video posted by the FatemiDawat has been removed, but is available here) This refutes their claim that the statement wasn’t clear, Moula’s speech was impaired, and Syedna Burhanuddin did not perform the Nass publicly.