That's not how it works. The brakes are more powerful than the engine, sure, but only at full braking power. Ask anyone who owns a rear-wheel-drive sports car what happens when you push both pedals at the same time and they will literally leave you in a cloud of smoke.
The RWD thing is definitely important here. Given that the majority of cars and a significant number of SUVs are now FWD, this doesn't hold water. Given it is the front brakes that are more powerful than the rears, and if your brakes are maybe a tad worn out, you might not be able to take your brakes from a dynamic friction situation to a static friction situation. In the mean time, your engine would just continue injecting heat into the brakes, which could easily overcome them. It might also be that he was not braking with the full force initially, meaning some degree of heat saturation may have already been present.
I could rev my engine while pressing the brake on a 2014 Honda Civic (helped with not going backwards when I needed to start moving from a standstill on a steep hill). Is that modern enough for you?
(On the other hand my 2017 Subaru Forester does not do the same; thankfully it has less of a tendency to roll backwards when releasing the brake on a steep hill.)
But, if you own a reasonably modern vehicle, try it :)