If the defender falls in the direct path of where the airborn shooter is potentially going to land, you have to protect the shooter. I call the block and go a step further. I warn the defender that if it continues to happen I will hit him with the "T". Keep in mind that a slow whistle is important here, you want to see the entire play before you blow it here. If the shooter lands safely to the floor its a great time to inform the defender that it's not going to happen again and this typically keeps him from doing it again.
As far as the unauthorized "get up" mechanic, I think its helpful so the coach atleast sees that you have seen the action and in your opinion nothing illegal happened. Sure he will tell you what he thinks but IMO it helps.

I have heard that line or statement for almost my entire career as well. I have never followed it and somehow I have done just fine. I do want to know how players get to the floor, but never call something just to make anyone happy. Most of the directives that I tend to get are usually surrounding codes of conduct of players or coaches and how the assignor will support you if you call a T. Almost never are we told to call a certain kind of foul stronger than the rules state or what is a POE. If you cannot officiate you will not get hired or stay hired in the first place. Guys around here tend to trust their staffs and your schedule reflects that trust.

Peace

If they fall INTO the path of the shooter, they probably don't have LGP and will have committed a block without regard to anything else.

If they fall IN the path of the shooter, from a position already in the path and away from the shooter and the shooter lands on them, the shooter would have landed on them anyway and the fall away only reduces the contact.

Don't use the get up mechanic. It looks horrible. Talk to them if you must, but not the get up waive.

Most definitely! IMO, that "mechanic" generally means, "ooops I got caught by surprise because I was watching the ball instead of the defender & I dont know what to call."

It may look bad, but that's hardly what it means.

I never use it, I say it, along with "don't do that again."

Reserved for the obvious fakes.

After breaking down film of the games that I've worked, when a partner used it... 90% of the time when I pause the film just before the crash, their eyes were NOT on the defender. Their head/body is where the ball is (press play) the crash happens & their body language suggest uhhh-ohhh, followed by the get up mechanic.

When you know how to do it properly (not call validation) & what to look for (positioning, presence, believability) tape dont lie.