Some detail missing from @4RNR's post is the fact that the safety/quality and condition of some of the firearms being carried precluded loaded chamber carry. That, and the variations (or even availability) of holsters for those sidearm.
Factor into that equation the level of knowledge and experience of their Firearms Instructor Cadre at the time in the use of handguns, and the methods of the time become understandable. Hell....American policing at the time was using training methods that we would consider suboptimal, too. And the American military was also training empty chamber carry for semiautomatic sidearm. Remember....this was Israeli military training we're talking about.
In context of the time, it's understandable. The total fail is that anybody today is still teaching or advocating any of this stupidity with modern firearms, modern holsters, and better training methods available.