I think it's important to remember that he has ~40 slides in reserve to talk about the specific points that investors want to cover. These 5 slides are fantastic and will cover the bases that you want in a short meeting but I don't think we should gloss over the point that there is a deep well of hard data to draw on if the investor wants to.

Also, demos rock. If you took away the demo I don't think this approach would work. So, I'd rewrite the title as "A pitch deck with 5 slides ... and a demo ... and 40 backup slides." (not really but I think all three sides need to be there for the 5 slide deck to work :)