A New One for Me

[MountieSB]

Here was the call on the field (I was a true spectator, not an umpire, coach, or parent - completely a disinterested party):

Both R1 and BR were called out.

Because I was just watching and didn't hear the explanation on the field, after the game I asked the umpire why there were two outs (because I'm still learning). He said with less than two outs, on a ground ball hit anywhere, a runner on first base (R1) has to advance to second base - she has no option. Once R1 achieves second base, she could return to first base by touching the bases in reverse order. His answer was confident, so I didn't question further.