That was not the question posited. If I saw a violent rape in progress intervention is a must. As fo an 80 year old man, unless he is exceptional, let him call the cops. The answer is simple to the posited question the people don’t act because they fear retaliation from the government or the perps.
The bullet coming out of an 80 year old’s pistol is moving just as fast as the bullet coming out of a 25 year old’s pistol. That is why Sam Colt’s invention was called the equalizer. I will stop any forcible rape in progress the fastest way that I can, be it a piece of rebar, a 2X4, or a 9mm JHP. Period. Then I will call 911.