Defenseless doesn't mean you can't contact them. You just can't target them. On a return a high hit could be legal against other players, but it would be targeting against a kicker or passer.
Is language the problem, or is the constant search for relieving the responsibility of judgment the issue? I don't argue with your conclusion, but that simply is NOT what the NCAA "Samples List" says. The list STATES: (c).......or during the kick or the return. (i).......any time after a change of possession.
When a kicker or a passer is finished their unique and defined action and chooses to participate in whatever is then happening, he becomes a PLAYER and all players are subject to the same consequences and responsibilities, or at least should be.
What we do is all about perception, interpretation and judgment, and how well (or not) we apply those traits. Sample lists can be extremely helpful, to form our perceptions and interpretations but they only contribute to our final perceptions and interpretations, along with all sorts of additional inputs, including mistakes, challenges, arguments and a lot of serious study and experience
If only there was a "Silver Bullet" or a magic pill.