[drakonka]

It seems like the heated argument part could have been avoided if both parties assumed each other's competence.

If A says they've already tried something, B could have believed that they did and that they did so with competence. A then even tried it _again_ to show B, but B still didn't trust that their coworker was doing it right.

I think it should be encouraged to double check each other's work. Often we _are_ missing something. But "Maybe you're missing something" is not a constructive contribution. At that point, B could try the thing themselves to see first hand what indeed, if anything, was "missing" instead of offering an unhelpful comment. Or suggest that maybe "we're" missing something, and then offer a concrete suggestion for how to modify the approach for another attempt.