Streaming Online - WatchESPN
Starting about the 1:26 mark, the Oklahoma batter-runner hits a ground ball to the first baseman, avoids her tag, and is initially ruled Safe at first base.
After a protest by the TAMU coach, the umpires rule the b-r Out for running out of the base path.
In reviewing the video, another possibility is ruling the b-r Out for stepping back toward home plate to avoid the tag. Obviously the umpires did not make that ruling as the runner on second base was allowed to advance to third base.
The question: What constitutes a step backward? If you were to draw a line perpendicular to the foul line through the b-r's feet, she clearly takes a step behind that line, although the step is not directly towards home plate.
Maybe the NCAA has defined "backward" for this case somewhere along the way. Maybe this is a Steve question.
And, sorry, I don't know how to grab just the snippet I need from the video.