You can do the same with a video. You pause it, get on a relevant IRC channel or internet forum and ask "what does she mean by X at 23:51?" Or you Google the term or process you were confused about and find someone else's explanation (I have personally done this loads of times). Or you turn to the person you're watching it with and ask. Or you call up your study group on skype. Do those two latter things usually happen now? No, but they easily, easily could if this type of learning became mainstream.

Is having a professor there that you can ask immediately in the moment (and interrupt the lecture for the other students who understood the material) worth $1000 per credit hour?