Crowd getting kicked WAS PGL's fault.

There isn't any law that says you cannot host event that goes over 24:00, but.

They had registered the event in wrong category (when registering event for your local authority, you are asked which kinda event it is, for example concert, sport event etc.) which means the event wasn't allowed to continue after 24:00. (The category which they used to register this event, is category which doesn't allow your event to go on after 24:00)

They are working with some local company to try change their events category for tomorrow, so even if Semifinal #2 would go to 24:00, the crowd would be allowed.

EDIT:

More specific. This major playoff part has been registered as a 3 different events, not as a single 3-day event. Which means for example, now "PGL Krakow day 1" event is going, and it's registered to end at 21.7 at 24:00 local time. Due to that, they had to remove crowd, as after 24:00 there isn't anymore officially event going on.