At what point can they report "We struck Oil?" When they smell it, just find a trace of it, hit a gusher, after the quality is assessed? They have to have some sort of objective test as to when they will issue a PR. I have to assume it could be days later, but it is just that - an assumption.
All things considered, however, patience is very important. For all we know they already hit oil and are waiting to analyze the situation before issuing a PR. Wouldn't it be a real bummer to find that they actually hit oil and you sold your shares at a nickle? HA HA HA!