i'm so sad that you weren't here with me.
I got to have one of those tough 'you're royally screwing this up' conversations with an engineer. I even got the boss' permission to threaten firing the guy.
For a non-confrontational gal such as myself, these conversations are more than a bit trying.
But you would be proud. I gave him a polite what-for. I didn't back down, i didn't do anything that would make me feel like i needed a shower afterward. I presented my points, sternly but professionally. And his reply - silence. As MB said, you can't defend an argument when there's no argument for your defense.
So there, i had a nice big professional how-do-you-do and i won.