Is this obstruction?
 

Batter hits a chopper to the short stop who gloves it and throws toward first the throw is a little inside and the first baseman reaches across first base to glove it. She hits it with her glove and deflects it toward the fence. As she reaches for the ball the runner is coming in and gets clotheslined by the fielders glove arm going down hard.
Obviously, it's mostly HTBT, but what can you tell me for calling something like this? The umpires on the field didn't call it (NCAA game) but I'm wondering if that's because fielders get more leeway there. My thought is that since the fielder didn't have any possession of the ball, she has no out for this in ASA or NFHS, yes?

You're right, it sounds like a HTBT...

For ASA and NFHS, it sure seems like obstruction. The fielder did not have possession of the ball, and the runner was definitely hindered (I would consider a clothesline a hinder).

The only other thing I can think of is that perhaps the umpire on the game judged that the ball, the fielder, and the runner all got to the same spot at the same time, therefore, no violation.

From what I have been told by my college assignor, we are to use the "is the fielder doing what she is supposed to be doing?" philosophy when ruling on obstruction.

This is most likely a no-call in NCAA as long as both the BR and F3 are both making legitmate softball plays and not doing anything to intentionally obstruct or interfere. (A.R. 12.14.3.2)

In NFHS, this is obstruction because the fielder neither has the ball nor is attempting to field a batted ball.

Agree.
The example put forth in A.R.12.14.3.2 is almost the exact play as in the OP.

NCAA still recognizes the "about to receive" caveat to exclude them from an OBS call. If the ball reached F3 prior to the runner, that requirement was met.

OBS in ASA & NFHS and I don't HTBT to make that determination.

Good point.