Basically, there's indeed a loophole.
When the police arrived on the scene, they wondered on what charge they could remove the protesters and still follow the law. They can't remove someone from a house if the law doesn't give them the authority to do so. There was absolutely nothing that they could do to get the protesters out.
Fortunately, the protesters ended up deciding to leave, since they had already been in the building for seven or eight hours. If they had wanted to stay there, they could have done so, since nothing was stopping them.
Nothing in the current legislation is adapted to the agriculture sector.