There's an analogy I could make if what a mental health professional once told me is true. A stressful situation often leads people working in that environment to become much closer emotionally.
While planning for construction of a new psychiatric unit, a psychiatrist told me there are a lot of affairs among workers on psych units due to the stress they're under caring for difficult patients.
That was one man's opinion (maybe he had one of the affairs but I didn't ask) but it seemed to make sense. Maybe there's a psychiatrist or mental health worker on the Boneyard that can comment, but the analogy I see is the lawyer and client just went through a long period of great stress and may, if the video is real, just be letting go and having a good time for a moment.