Well, this thread died quicker than it started.
My point when I started typing was to point out that R2 being thrown out at 3B had nothing to do with the OBS. As I typed I realized all the different issues that could rise out of a situation like this.
I don't know if I would be too quick on the INT for drawing a throw though I could see an umpire making that ruling.
And can R2 be called out more than once if it was obvious she did not hear the BU? Or for that matter, what if the BU already has in mind this interpretation, makes no out call and then R2 gets thrown out at 3B?
R2 could have checked-up if hearing the original out call for passing, but then are we looking at the OBS or umpire's appropriate ruling as the cause.
What if R2 continued, but B5 is thrown out at 2B prior to R2 getting to 3B? You still scoring the OBS runner since she hesitated off 2B and probably would not have scored by the time of the out at 2B?
Hell, you can do an awful lot of fishing with this can of worms.