Depends on the nature of the incidents, the length of time betwen them, what type of trends the company thinks it is seeing, and a host of other things. There's nothing to stop them from doing so, it's a judgement call they have to make based on their rules and standards.
It all depends on the company. Where I worked if you steal a drop of gasoline you're out the door. Incidents can have different levels of severities depending on who, what, and where you are.
