Paulo,
What kind of tape are you delivering on, BTW?
Quite a discussion. From a technical standpoint that guy sounds like a troublemaker and doesn’t quite understand things. The only complaint they could be making is that YES 25p will look “jerkier” than 50i… or in other words, look more like shitty video camera vs film.
There’s no way to make progressive look like that. You could force the fields out of order so every frame is “jaggy” but that would look TERRIBLE played back in real time.
I have a suspicion that when you field-by-field in Avid, it’s duplicating the field being currently viewed so that you see a whole image, vs seeing only the 1 field and black filling half the screen. So yes, it would appear as if things only change every other frame.