Actually, the rules applies BEFORE 19:30 too. If I insult just before the match start (during doing last-minute drops an extra time), that player should be banned from the match. It's as easy as it gets, right? While you and your opponents are on the server hosted by the ECS; you pay respect to your opponents - in a sense, they're also your peers (we are a small community, remember that) and as fellow tournament players must be, no matter how much you hate them, treated with some remote decency. This SHOULD apply to the outside as much as possible too - as in, not on the ECS servers -, and if gone overboard should be managed by the admins too (chasing and harassing opponents isn't called "respecting the opponents" either, now is it?).
While it seems Fietta could probably manage it in a smoother way, the players didn't respect Fietta as an admin either, which is like a football not going of the pitch when he gets a red, and ignores the yellow he gets even though he knows it's hurtful to do what he did, hence the warning.