You make the call

[woolnojg]

Let's see.
BR passes by 1st on a base hit to F6.
No mention of BR attempting to advance to 2nd.
R1 returns to 1st in a force situation. He then goes past 1st into foul ground and then returns to 1st base.

I've got BR legally acquiring 1st base with no attempt to advance. Therefore he did not pass previous runner. BR safe.
R1 has no legal right to 1st base and is tagged in a force situation prior to reaching his next base. R1 out.

Luciano's law:
Always penalize the person/team that caused the problem.