With no outs and R1 on 1st base, the batter (B1) hits a sinking line-drive to rightfield. The right fielder dives, traps the ball, and the field umpire correctly signals "safe, no catch". B1 saw the safe signal and took a wide turn at 1st base, but in doing so B1 very briefly passes R1 (who thought the ball was going to be caught by the right fielder so was only a few steps off 1st base).

 

The defense throws to 2nd base to easily force out R1. However, at the end of playing action, R1 is standing on 2nd base while B1 is standing on 1st base.

 

Who is out and who is safe on this play?