I had that experience once. To make it more interesting, I was the lone physicist in the entire company, and a brand new employee in a huge meeting full of company brass. I told the product manager that something wouldn't work. He stood up from his chair and shouted at me.

He didn't know that I had some "trial by fire" experience in previous jobs, and I calmly stood my ground. What he was proposing violated the second law of thermodynamics.

Thankfully the person running the meeting proposed tabling the idea. But it remained in the product requirements document for the duration of the project.

I learned that sometimes math and physics are best discussed privately. ;-)