I don't remember him saying anything of the sort. Read what he really said. ("The speed of a falling body is independent of its weight.") Think about it. Maybe you'll figure out why he keeps saying it!

I suspect what he is getting at will be clearer to you if you reverse what he is saying and see if you think that is correct: i.e. if you don't believe the speed of a falling body is independent of its weight, do you feel it is dependent on its weight?"