All 3 Minnesota targeting ejections (Oregon St @ Minnesota - Video)
 

1st
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2nd
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3rd
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Peace

IMO, #1 & #3 are easy.

I have a problem with #2, however. The defensive player had already committed before the slide began, and was indeed trying to tackle in the "hit zone". If the QB had stayed upright, it would have been a legal tackle.

I agree with both considerations; the defender's commitment BEFORE the runner changed his profile, and the fact the runner, dramatically, changed his target profile. Although, it wouldn't be a bad idea for the Minnesota coaching staff to hold a really in-depth discussion about the "Targeting" rule with the ENTIRE team.

There's nothing in the rule about "committing" by a defender. Any defender is responsible for the HIT, and we must emphasize that although "tackle" is very broadly defined in the NCAA rules, the TACKLE and not a HIT is what is part of the game. There's no need to tackle or even touch a sliding player, so defenders must learn to either 1) lay off; 2) aim low and hit low; or 3) dive over.

Don't add a layer to the rule that doesn't exist. Its taken me a long time to get that idea through my head (football and basketball), but overthinking things will always get you in trouble.

Agree, but this defender had already committed to a move that would have resulted in a legal hit had the QB not made a late slide. He can't change his course in mid-air once he recognizes the slide.