Where I live, you can get a variable rate mortgage that's advertised at 3%. More than likely, the bank will look at your credit rating and offer something lower. Even if they don't, that's half of what the video is showing.
Likewise, a 4% return on investments seems unreasonable. The same bank with the 3% mortgage is offering a non-cashable GIC (which seems to be the Canadian version of a CD) which pays 2.3%. That's only a little better than half of what's shown in the video.
As for housing prices, it's very hard to find identical houses available for rent and for buying, but here's what I found:
For rent, a 3 bedroom, 1.5 bathroom, 1100 sq ft townhouse for $1500/mo. For buying, a 3 bedroom, 2 bathroom, 926 sq ft townhouse in the same area of the city for $225K. It's not apples to apples by any means. The one for purchase is smaller, plus it's a condo so there will be additional fees on top of the regular things you'd pay for in an owned house. In spite of the differences, $3K of rent does not equal a $1M house in my part of the world.
I plugged the numbers into the New York Times rent vs buy calculator that was mentioned elsewhere (http://www.nytimes.com/interactive/business/buy-rent-calcula...). With these two properties, with these interest rates on the mortgage and investment, with local taxes and utility costs applied, buying is better after three years.
That said, it might not be all about cost. If you like to move around a lot, maybe renting is better because not renewing your lease is easier than selling a house. Maybe renting is better because you don't have the savings for a downpayment or don't qualify for a mortgage. Maybe buying is better because you like to do the handyman type of stuff and rarely move.
There's all kinds of reasons that renting or buying can be better, which is why I don't buy blanket statements that say "renting is always better" or "buying is always better".