Working on the next task card of my current project when I came across a small screen with a drop-down and two text input boxes all wrapped up in one form. Nothing in the specs about their behavior so I went and chatted with my boss. He thought it was obvious what to do but I asked that it be redesigned because it was confusing. Here's what I thought it was supposed to do:
I argued that it was confusing but the person who created it said everyone would understand. Two more people had wandered in on the conversation and one said it won't be confusing because we'll document it and another argued that I had reversed the order of what should override what. That pretty much ended the disagreement. I should have the new UI layout in a couple of hours.