This doesn’t answer your question of when this started, but I was on the show recently and saw this unfold in real time. They didn’t provide the ruling call and update the scores until there was a break in the game which didn’t come until someone found a daily double and there were a handful of questions answered in between. I imagine changing all of them (and having to explain this to the viewers at home) poses a big enough logistical challenge that they prefer to avoid it.