It is available at 43’29’’ in the video of his lecture:
In each of these boxes we have 80 dots. Same number. 80 dots here, 80 dots here. Please don’t count them, but I swear there are 80.
When leaving the auditorium I mentioned to him that they were not 80 dots in the left box. He reiterated there were 80 dots in each and that he had asked us not to count the dots!
I followed up by email and pointed out that one didn’t need to count. The left box has 10 columns of 8 rows, so for there to be 80 dots, all intersections need to have a dot. It is visually obvious that this is not possible. If you zoom in on the screen capture of the video, you should be able to count 68 dots in the left box and 75 in the right, so neither have the claimed 80 dots.
It would have been easy to create slide matching the content, but instead Prof. Grinker asked us to trust his lie and then didn’t bother to respond to an email about it compounding this lack of veracity with a lack of respect.