I agree completely - but the course designer is undeserving of your charity, IMO. However, the instructor in the video is mounting a most determined defence of the notion that the phrase is 'wrong', ascending to airy heights of pedantry, and refusing to allow that it's even a common 'misuse', and is supported in this latter contention by various posters in the Comments, who, as I say, claim to be quite unfamiliar with it. Hence, my 'straw poll' here.