or that negative-G pushover with the coke-bottle hard against the headliner is kosher..
I call BS on that statement. I saw the plastic coke bottle float slowly up and kiss the roof. The aircraft would have been pulling just a tad over 0 negative gs. I have seen much higher gs negative and positive sprung on me by nature. To my mind a completely controlled planned manoeuvre is much safer than a surprise one of unknown strength. I think a lot of pilots think they are 1g negative and freak out when actually they are at zero g and weightless. At 0g there is not much stress on the wings. Work it out.