Someone was wrong about something. I explained to the person very kindly and with "social tact" how they were wrong and why the right answer was, in fact, the right answer. Subsequently this person became passive-aggressive in their actions. Now, I am explaining to a third party what occurred, and I want to convey that I was very cordial or congenial while explaining that the original person was incorrect, so as to say that it didn't warrant the outcome.
- Would congenial be appropriate here?
- Is cordial better than congenial? (What's the subtle difference?)
- Is there any other word that would be better suited to convey that I was very socially sensitive and friendly in the way I presented to the person why their answer was incorrect?