"Also, an issue about being stubborn about the truth is that there can be as many versions of the "truth" as there are actors in the situation."

I'd strongly disagree. Different people may have different pieces of the truth (ie the truth could be "Either person x's approach or person y's approach will work"), they might have different perspectives on the truth (ie the truth could be "person x is right about a, b, c, and d but not e while person y is right about e, f, g, and h but not i"), or they might be arguing about a subject where there is no real truth (see religious people for powerful examples). But where the truth exists it is singular.

When presented with conflicting ideas, the goal is to determine if one is correct or they both are correct. Throwing your hands in the air and saying "The truth is subjective" is a cop-out.