I could be wrong, but I seriously doubt that Tony Morris has PTSD.
What I have noticed about Vietnam vets in general is the following:
1) Those who saw little to no action tend to enjoy talking about the war at every turn for some reason. They also tend to embellish their role in the war.
2) Those who brutal action on the front lines do NOT like to talk about the war at all... ever. Especially those who still suffer from chronic PTSD.
Since Tony never wastes an opportunity to talk about Vietnam, that makes me believe he saw nothing that would give him PTSD. Maybe just a few bleeding patients every now and then. Just my humble 2 cents based on my own observations (not based on any medical knowledge).