Cal Ripken baseball rules

Question
Question about Cal Ripken baseball rule interpretation...this situation was presented during the training of umpires for our organization.  

Bases loaded (R1, R2, R3).  Batter (B1) hits a ground ball to the second baseman who bobbles the ball and does not have a play at first.  R3 forgets the situation and remains at third.  R2 and R3 are now standing on 3rd base.  The second baseman throws the ball to the third baseman who tags R2.  Umpire should rule R2 is out.  Is this correct?  Thanks for taking the time to answer.

Answer
Chris,

I am not experienced in Cal Ripkin rules. However, I don't see how this situation would be ruled any differently than it is in every rule code I've ever umpired.

In your situation, R2 is not out. R2 was forced to advance, and until a preceding runner (R1 or batter-runner) is put out, he must advance to 3B. In effect, the base belongs to him. Additionally, R3 is forced to vacate the base.

So, R2 would be safe. If F5 touched the base, R2 is still safe. In this situation, R3 would have to be tagged or home plate touched while holding the ball.