The news report and an interview with the restaurant owner who served them breakfast that day, makes it sound as though the two pilots were friends, and the flight may have been a planned flight "together". It would not seem odd to me that two fellows who owned the same type of helicopter would go flying together. I've done a lot of civil formation flying, it requires good planning, agreement on roles, discipline in flight, and an escape plan - or... lots of distance between the aircraft (and still the escape plan!).