Nutters like this are a danger to themselves & will be untill they learn the hard way! It's a bit like your first parachute drop from a static ballon. 1st time is a nightmare after that it gets fun. Freefall is even better;-)
When I worked offshore in the Arabian/Persian Gulf we used this type of crane. Part of my job was to change the bulb in the aircraft warning light at the end of the jib,and assist in rope changes and maintenance. Although it was "only" 80 metres high I was never really comfortable doing it although I am ok with heights. When you walk out on the jib, it moves up and down slightly as it is so finely balanced. We certainly never played about out there.