Butch, first let me tell you how nice it is to read about an experienced shooter helping a new one get off to the right start. As you see it takes time and effort and sometimes you run into things you can't figure out, but with the new shooter shooting eight inches high you have to save him or he will surely quit in frustration or trade guns or whatever - some bad choice that could have been prevented with a little guidance.
Some ideas. Pick any that may apply.
1. He doesn't know what "stacked beads" means. I don't mean in words, I mean on the trapfield. I remember that it took me a couple of years when I started to get the idea and a friend who started with me still hasn't got it right. What you should do it take a gun that lets you stack the beads in the meaning as you understand it and point it at a mirror and see where your eye is relative to the receiver. My bet is that you won't be able to see the whole iris of your eye, probably only the top 2/3. More or less.
Then have your student point the empty gun (checked several times and every time he repeats it even when you _know_ it is empty. It's a good habit for him to get into,) at your eye and see how much of his iris you see. If it's 2/3 (or whatever you saw in the mirror) then you at least know that you are using the same meaning when you talk about "stacked beads." If it's different, do whatever it takes to get his eye down some.
2. He may be jerking the gun up when he fires. You may try light shells or more shots or whatever makes him jerk less. Show him how to squeeze the trigger slowly so he hardly knows when it will go off. If he shoots several high and then one OK, stop and ask him exactly what he saw and felt on that shot. I've seen shooters who think that a whole-body-jerk is normal - look for that too. You can check this by pretending to load the gun and giving it to him to fire (he thinks it's loaded, of course.) Some people just seem to jump out of their skin.
Whatever it is, Butch, find out and fix it. Only you can save him - and only you will.
Neil