Decent review. Not 100% correct - but close.
The original gun was DI, which Colt got uppity about given the fact the patent was sold to them.
So Stoner converted the gun to a piston.
It’s interesting as the two guns that are used are at C Reed Knight Jr’s Institute of Military Technology, and one of the uppers Reed has is a much less photogenic one that has a gas tube.
I also find it odd that the whole ‘easier to manufacture by less technological countries’ pooped up. People said the same about the FN CAL and FNC.
What it is, is that it is cheaper to make stamped steel receivers in volume than it is to forge aluminum and machine it.
Plus the square carrier is easier to machine, as it doesn’t also need a lathe like the circular AR carrier.