Where did the OBS occur?

[CecilOne]

There are really two aspects involved:
- which base the runner would have reached w/o obstruction
- where the runner was out out

This time, the judgement was that the runner would not have reached 2nd even w/o obstruction and it is clear the runner was put out between 1st and 2nd.

The phrase "B1 alters path to round on outside of bag or on orange part of double first base" might be the key. If the BR "alters path to round", then I could think OBS from going to 2nd. If the BR altered to "orange part of double first base" just to reach and overrun 1st w/o immediately turning toward 2nd, then I could think the OBS is before 1st.

If OBS between 1st and 2nd, runner gets awarded 1st because of the "not put out" aspect. If OBS before 1st, runner is out.