The same reason he didn't record his disfellowshipping meeting.
I myself personally believe that he did record his JC meeting. I think he is just hiding the fact that he did. Just think, if you had some damming evidence against watchtower you would want to have all the physical evidence you could get. He just does not want to tell people he has it, so they do not bug him to release the recording because there is very damming information (talk of pedophilia or suspected pedophilia...etc.) and some kind of "blackmail" going on in that recording. From WT or Lloyd or both. This would make the statement of "I'm not going to record it. I'm not going to make any efforts to record it and the reason why I'm not going to be recording it is because I don't want anything to hide" make sense. He wanted to be able to talk freely (bully, harass, blackmail...etc.) and not have to hide what he says and how it was going to look or be talked about in the exjw community. If he was going to record it to be released, he would not want to go into detail and the JC was the only chance to confront WT.