Alright, so I had Contractor #4 come over tonight and he gave me some info. He said that the outdoor condenser was not cleaned, therefore, giving off the wrong readings. He saw everything was working as it should, but the motor in the attic was making some humming sounds. After running it, turning it on and off a few times, the motor stopped working! He powered it off and it started back up with the humming noise. So for now, the A/C works as it should, but the motor is on its last leg. The tenants will be with minimal A/C, and a humming sound, for the weekend.
He wants to give it a few days to observe if anything else comes up.
The funny thing is, the tenant told me that the motor was making some funny sounds before contractor #3 even did the evac/purge. Contractor #3 said that the motor checked out ok, yet recommended the evac and purge anyway, due to the fact that the readings were fluttering etc The outside condenser was filthy according to this contractor. Could this have been an improper diagnosis from contractor#3?