I'm surprised no one has made at least one of two compelling arguments:
1. If you were to get pulled over and informed the officer his image and words were being recorded, wouldn't that indemnify you from prosecution for recording without consent?
2. When you get pulled over, 99% of the time, the encounter is already being recorded by the officer's own dashcam. First, why doesn't the consent apply here also, and second, if the encounter is already being recorded with the officer's knowledge, why would a second recording, even if it's existence isn't known to the officer, be prohibited?