Basically, assuming you do meet the "lived in last 2 of 5" requirement, weather you get the full exemption or partion exemption, depends on how the property is classified at the time of the sale. If you are the last one to move out prior to the sale, then you have "unqualified use" that will reduce the exemption amount. If the renter is the last one to move out and you still meet the requirement, then the full $500K is excluded.
