If you had 4 people the video was going trhough the JVB for sure. Since a Jitsi Meet installation uses multiple components, maybe you didn't shut them all?
Video shenanigans can be a dark art, but not that magical ;-)
Very possible the docs are wrong - im not a jitsi dev, so I wouldnt be able to confirm or deny without poking around. BUt they do specifically state that (as linked).
That said, it is worth pointing out that this thread is specifically about videobridge (i.e. scaling beyond a full mesh).
Traffic only goes through the server for users behind NAT, triggering the TURN path.