The silver fox whose name I can't recall lost me at the 'knock knock' joke. He can definitely rattle the witness. But O'Mara is breakin' awesome! If I had taken the bar and become a baby lawyer, O'Mara is who I would have wanted to grow up to be~!
His name is Don West - and if he lost you at the knock-knock joke, don't blame him; blame yourself. The knock-knock joke was meant to illustrate the importance of complete neutrality on the part of anyone chosen to sit on the Z jury. In a high-profile case such as this, such neutrality is of vital importance.
I will give you that it was probably a mistake to preview the "joke" by telling the jury they were about to hear a joke. Because it clearly wasn't funny. But it wasn't meant to be funny - it was meant to educate. What he SHOULD have done was tell the jury something like, "You all have heard of knock-knock jokes, right? I have one here that I will tell you about. It isn't meant to be funny, so don't expect to laugh at it. Rather, it is meant to illustrate a point which I will expand upon after you hear the joke. So there's this knock-knock joke that goes . . . "
If he had done THAT, he could have progressed smoothly from the telling of the joke to the illustration of the point to be made. His only mistake was in not previewing the whole thing properly, for which the media jumped all over him. It wasn't as bad as the media would have had us all think. Anyone with any knowledge whatsoever of jury selection would have instantly understood what he was doing.