Usually a halt comes when the information to be released is controlled by the company and there are several 'in the know'.
In the case of the permits, the situation rests with the Peruvian Gov't. They control the timing and conditions of the permit and SLI can report when it has received the permit. Besides I don't think that a permit is that big a deal. It's a licence to explore further.
Now if a drill core comes up with visible gold, that's a different matter and there is little that can be done to keep it a secret by the drillers or SLI site employees and to keep persons from trying to profit from it. So in such a case, a halt would be initiated in order to formulate a NR that would place all investors on an equal footing.