Gosh, a few comments about Dylan. I can't resist.
Dylan does fluff lines from time to time. Indeed, even his studio albums contain the occasional fluffing of words. He goes for the feel of the recording as much as anything and lauds the raw feel of those early rockabilly/r'n'r recordings he loves so much, irrespective of technical issues. In concert, there have been many lyric lapses. When he changes the words from those on the album, there are occasions when this is clearly deliberate and an involve complete new verse. Other times, it may just be covering a memory lapse. He also omits complete verses or changes the verse order.
The only Dylan show where I've seen a teleprompter being used was at the 30 Year Tribure concert in Madison Square Garden in October 1992. I believe that you can see it happening in the official video. Lou Reed was obviously doing so but then he chose a long, fairly complex and not that well-known song. I paid for my ticket there, avoiding "street prices", but it was arranged through a musicbiz contact, so I was sitting amongst a number of musicbiz/media types and one asked loudly what the song was called. I answered, not quite as loudly, but loud enough to be heard by several folk around. That and my English accent, I guess, resulted in my being quizzed (pleasantly) by a few people at the end of the show.
In more recent years, Dylan has been seen, between songs, shuffling laminated papers resting near the keyboard. Some have suggested that these were the lyrics of songs he sings less frequently in concert. I once tried to read them through binoculars from an elevated position and, to me,they looked like individual lines rather than whole lyrics, but I can't be sure. My theory is that he has some opening lines there (either of the song or of the verses within a song) and this jogs his memory, when required. He obviously doesn't do it when he is centre-stage.