Highlight Usages in File - Exit points

When I invoke Highlight Usages in File (Control Shift F7) on an exit point in a method (return or throw), some other exit points are getting highlighted. However, I can not figure out how is the scope determined since not all exit points are highlighted in all situations.
Can somebody shed the light on the rules of highlighting in this situation?
Also how can I make sure that all exit points in a method are highlighted?

Artem