What is the call here?

[youngump]

Originally Posted by IRISHMAFIA

You think you can compare physical assault to a poor defensive play?

Sure. Because one really good way to truly understand a rule is to take it to the extreme.

In this particular case, the thing you used as a difference between the two plays was maliciousness.(*) Unfortunately, there's nothing in the rule that let's you rule differently based on intent. Obstruction is obstruction whether done with malice aforethought or incompetence.
The thing I think you should have grasped on to if you want to distinguish the plays is more what Manny alluded to in his reply. That he didn't believe that in the OP the runner was impeded by the time she decided to go to third.
That is to say, the rule is that a runner need not be physically advancing at the time of contact for it to be obstruction as long as the contact impedes them from advancing before they have recovered from the impact.

If so, then we have this play even a little more ridiculous but illustrating the point. Towering fly ball hit to the same spot. We can finish this whole argument while the ball is in the air. F5 again takes out the runner. She gets back up and A) resets and is fully ready to tag when the ball is touched or B) resets but is still off balance when the ball is touched

A) This is not obstruction. (Eject at the end of the play but) she advances at her own risk.
B) This is obstruction. She wasn't fully recovered at the time she was ready to advance so the contact hindered her. She cannot be put out between 3rd and Home.

(*) My apologies if I'm overreading what you wrote. I took it as (ignoring the implied part about it being a stupid argument): the play you outlined is obviously obstruction because it was **malicious contact** which is nothing like the defensive ineptitude in the OP.