Indeed, although I am sure we wonder what aspect of commercial jet operation is served by demonstrating to the prospective customers sightseeing manoeuvring close to mountains, especially as they were probably focused on the Champanska instead.
I have done many demo flights when working for aircraft manufacturers. There is a tendency for the VIP's on board ( most of whom know SFA about aviation) to want to see the aircraft do manoeuvres that are outside of the normal civil operating envelope. Pressure can be put on the crew to demonstrate the agile manoeuvrability as the aircraft has low fuel and payload. Most of the time it is pulled off without consequences. This could well be one of those times it went wrong.