I concede that the example may have been poorly chosen. He could have checked this in the original research but not bothered to talk about it during the presentation; or maybe he screwed up. In either case, the original paper is available at his website for your assessment.
I concede that the example may have been poorly chosen. He could have checked this in the original research but not bothered to talk about it during the presentation; or maybe he screwed up. In either case, the original paper is available at his website for your assessment.