[Rich Ives]

A few thoughts

If you've been around sports (not just BB) for long enough you can pretty much recognize most forms of intent. You can tell by the mannerisms and actions of the players.

Using the kick: People who kick (contact object with foot) something intentionally ususally look at it to line up the kick. People who kick something unintentionally are usually looking elsewhere at the time.

If a fielder is chasing a ball and the base coach is attempting to get out of the way, he will be looking where he is running and/or moving away from the fielder, and it is unintentional thus no interference. If the coach is moving, but looking at the fielder like he's trying to "line him up" or intercept him - it's intentional.

If the on-deck batter aka home plate coach is on 3B extended and behind the play, is it reasonable to expect him to believe that a) the catcher will miss the ball AND b) it will bounce at him? If he makes a reasonable attempt to get out of the way, I don't see intent (kinda like the coach item above.)

You also need to look in the mirror. A "conspiracy fan" will always see intent, even if none existed. A laid-back type will see "accidental" everywhere.