I have to agree with TTF, that showing him a javeline will reinforce the over countered position.
If you look at the relationship of the direction that the inside knee is pointed compared to the direction that the feet are pointed, it becomes obvious that he does not have a strong inside half. He's being very passive with it. He can't be stacked and in a position of power if there is that much of a difference in where the two are pointed.
Here's a progression I might use to get him up and stacked, and to be stronger with the inside half. I call it a "shovel turn" progression.
1) Have him make turns on one foot, the outside foot, slightly lifting the inside ski throughout the turn.
2) Same thing, but lift the inside ski enough, and turn the inside knee into the turn enough to show the base of the inside ski to the outside boot (turn the little toe down and big toe up).
3) Same thing, but keep the tip of the inside ski on the ground.
4) Same thing, but with more emphasis on keeping the inside tip forcefully on the snow. I ask students to try to make the inside ski tip throw snow across the outside ski. This forces them to be strong in the calf and ankle.
5) Start the run doing the same as #4, but after a few turns, start lightly putting the entire inside ski on the snow.
6) Now the same thing, but more pressure on the inside ski. The intent is to have the same feeling with the position of the femur and shin while the ski is pressured, as you did when the tail was off the ground and pushing snow across the outside ski.
This progression does a number of things:
- Works on building balance skills
- Early pressure and edge change
- Early active inside leg steering
- Keeping a proper stance - forward - because you can't keep the tip down with pressure if you are back
- Forward-and-across movement to initiate the turn (as opposed to too lateral)
- strong inside half with upper and lower leg as well as foot steering
It will usually show a bit of a diverging inside ski, but because the pressure is obviously on the outside ski, it doesn't become a problem. And once the student puts the ski back on the ground with some pressure, the diverge stops because the ski is put down on its edge.