Well? It is funny and it isnt.
Its funny like playing with a loaded gun and pointing it at people.
Some will laugh especially the gun holder, but not the people being pointed at.
In small airplanes everyone needs to remain seat belted. If the passenger had
undone his seat belt and pushed on the pilot or steering wheel, it could have caused the plane to tilt or careen. In just such a situation the passenger could have been lodged between the pilot and steering wheel , or just lodged on the pilots back due to gravity and the aerobatics of the plane making any recovery impossible. There are many small plane crashes that are unexplained some due to bad weather, mechanical problems or just plain shennanigans like this one. The same as the fool playing with what was known as an unloaded gun…but loaded and someone gets shot. Guns and airplanes are not toys!