I would think the problem would be students pointing out this out to teachers like yourself and then explaining the flaws in Trevor's article and the student trusting what you're saying because Immelman is a Master's champ and gets a lot of rave reviews about his swing.
People often ask why is golf so hard. This is unfortunately a big reason for it.
3JACK
Golf Digest (Jul '08 edition) has some very good swing sequence pictures of Trevor Immelman. Frame # 6 shows 3 views at impact. FLW and BRW Right forearm on plane and pointing at the plane line.
This is the swing that has earned Immelman's swing much praise and is likely the swing with which he won the Masters. While Trevor may feel he is emulating the alignments he speaks of in the March '09 Golf Magazine article, in actuallity he is not.
Be careful what you ask a great player to do. He might just do it. If Mr. Immelman continues to work on poor impact alignments, he may just acheive them and play his way into the broadcast booth with another major champion.
Feel is not Real. Feel can also change from day to day or moment to moment. Alignments are always the same. Develop feel from mechanics. Beware what great players tell you what they are doing. They are tremendous athletes and can make almost anything work, at least for awhile.