Probabilities (up & down) in the contect of one-period binomial model (option pricing)

So, last year, I didn’t understand the binomial model for option pricing partially because I didn’t find the way proabilities were computed to be very intuitive. So, I went and watched a video from Wilmott ( http://www.7city.com/cqf_webcast.php?area=quants&outline=cqf&course=webcast ). I’m 17 minutes in, and the guy states that probabilities don’t matter ( and he explained it in the first 17 min). Now, question: Is Wilmott’s video consistent with the CFA curriculum? Why? Why not? Thanks

Please ignore this post. My question is answere on the 50th minute of the video. Great video Btw.