let me change this just a little. If the player near the base contacts the runner, casuing her to trip and roll past the base..... and then tags her with the ball...whatcha got? I KNOW thats a big if...

No, I'm attempting to NOT reward the defense for CAUSING a runner to be incapable of performing a controlled slide.

The two cases I mentioned, I will be more specific on, if it helps.

1) Runner is running full blast near the baseline, where the shortstop is standing 8 feet from third base, zigzags around F6 to the left, tries to stop her momentum from the zigzag by sliding or diving, and misses or overslides third base.

2) Same runner is instead inadvertently bumped by F6, again causing her to miss or overslide third base.

In both cases, the OBS occurred between 2nd and 3rd and protection is deemed to be just to 3rd base. Are you ruling this runner out? If not, how, based solely on the rule as written, are you giving her 3rd base.

To the point of sliding. This is strictly a runner's option. OBS does not force a runner to slide.

A tripped and stumbling runner going past a base is an involuntary action caused by the OBS. A slide is an act totally controlled by the runner.

Dress it up any way you like, it is still apples and oranges. In the scenario given, the runner is out.