The reality is that everyone was trying to feel the other side out the first day and a half on the ATL Crew Room week. It took some time and back and forth for everyone to get the ground rules ironed out, but by the time they did, everyone was just fine.
Heck I saw one of the FO reps in ATL offer to buy some of the DPA guys coffee later in the week. They all seemed to be very civil.
By the end of the week, everyone was fine and dandy. Any new event like this is going to take a few days to get all of the miscommunication worked out, and this was no different.