It can be difficult to keep cool and level-headed when trying to straighten out problems with confrontational individuals such as what you are describing from the service manager.
It might help to give things a day or two to rest then go back to the dealership to try again. Give the service manager another chance to see things your way. If he won't cooperate, try the dealer manager or owner. If they won't cooperate, you might as well call Mitsubishi Corporate.
See, you have clear documentation of a problem that the dealership cannot deny. If the dealership service department were doing their job correctly, it is my understanding that these results are to be posted to your Mitsubishi service record and should be available to Mitsubishi Corporate to review.
To me it appears you have caught this person in a lie, as you have prepared yourself with the knowledge and understanding of alignments and were able to interpret the results right there in front of him. You caught him lying, and that embarrassed him and put him on the defensive. No surprise really.
This shouldn't happen to anyone, much less you. And it sounds as if that man is not really ready to be a service manager. From that perspective, you might as well skip over dealing with the service manager and give the dealership manager or owner a chance to make this right. And share with them that if this cannot be resolved at this level you will be calling Mitsubishi Corporate for guidance.
I wish there were more we could do to help, but I think you have what you need to see this through. Do keep us updated Premeir620 - I hope you are able to work this out. :)