Outstanding post genedebs. I can verify that the airline industry is identical. Management put video cameras in the bathrooms at our flight ops building during our union struggle, so we couldn't go in there and have private meetings, but when they wanted to do that in the airplanes, our Union rebelled, since that effort came out right after their memos admonishing us not to ever talk about management or Union matters when we were flying. They had previously been illegally downloading the voice recorder at the termination of flights. A maintenance guy was ordered to plug into the black box and download the entire flight, even though contractual language forbade this.
Just as you say, trash talking is all that kept us awake on boring gloomy flights over the ocean (the sterile cockpit only applied under 10,000 feet.) And in the golden era of Aviation in the 70's and 80's, we too had a saying: "Nothing goes past the cockpit door" since management would use any perceived error to get rid of Union organizers only. We called this "The sanctity of the cockpit" and we were free to discuss maintenance or operational problems without fear of finger-pointing by big brother Monday morning. Airlines that didn't allow this had terrible safety records overseas. Crews were afraid to talk about any FUBARS or problems, since they might be blamed for it.
We also used the buddy system, where a tired crewmember got a nap while the other ones watched the shop. This was a huge safety boon, used since aviation started. NASA concurred on their sleep studies saying that a 20 minute nap in cruise led to a much safer operation. Crews made 70 percent less errors in the approach and landing phase when they took a short cat-nap in cruise. But the FAA couldn't swallow it, since it was such a political hot-potato, and it never made it into regulation, that I know of.
Now cameras are coming back in the cockpits and they no doubt will harm airline safety if safeguards are not followed concerning their use. If they are used just for crash investigation, they will actually improve safety.