Found this play on youtube:
https://www.youtube.com/watch?v=jewBHBP_9g4
What I saw: R1, R2. Double steal. R2 caught in rundown, returns to second. R1 reaches second. Both runners tagged while on second. R1 called out. R2 then runs back to first.
Why did R2 run back to first? Is that legal?
Also, If R1 stops and R2 "passes" him while returning to a base, is either of them out?