I understand a few slides were removed from the version on the web... but did the version as presented include 'hard core porn', graphic depiction of actual sex acts?
The pictures were mostly of scantily clad women. I think one involved oral sex.
He flipped through the images rather quickly, so it wasn't exactly clear what was going on in them, which actually made them seem a bit more risqué than they probably were.
My judgment that the talk was over the line comes from how I felt quite certain that women in the audience would be uncomfortable.