Guess I will call for a second opinion. We actually do have an attic fan (along with almost full length ridge vents), I had to replace the motor two weeks ago and I was sweating to death in the attic and lamenting the shitty AC upstairs, which is what prompted me to call the tech in the first place. I don't ever recall this issue so something mustve changed in the past year.
Sad thing is half my job is refrigerant thermodynamics (on a city-sized scale) but I've never bothered to do the calculations for the AC unit.
Onward...