[BoomerSooner]

There are plenty of ways to avoid a collision in this situation without the runner slowing down to the point of being putout. The first thing that comes to mind is a well placed/timed slide. The way I look at OBS in a situation like this is there must be something that directly and necessarily influences the runners progress. If runner's progress is altered by her own concern for a collision and it turns out it wasn't necessary (this case is one example, another is at first base when a runner slows down to avoid contact when the fielder wasn't really in the way), I'm not calling OBS.

I can't sit out there and try to play the "well she slowed down because she thought she might run into the fielder, or the fielder was in the base path (when the runner was only halfway down the line) so that might have caused her to slow down resulting in an out". I'm going to look for something more concrete before I make the call.

When I played baseball, I was always taught to go hard, run the play out, and just let the umpires take care of the rest if something happened. Now I think coaches and players are so caught up in worrying about these things that used to be the domain of the umpires (like OBS and collisions).