Dead Ball Advancement

Question
There was a runner on first base with less than two outs.  The ball was popped up into shallow right field and the second baseman went out and made the play.  Noticing the runner was caught off first base and trying to get back, the throw was made to first to double-off the runner.  The throw got away and entered dead ball territory and the runner was award third base.  Umpire stating the runner already had first base and was awarding an additional two bases.  Is this correct.  My argument was the runner was trying to get back to first when the thow was made and therefore should only be allowed second (two bases, the base he was running back to plus one).  Who is correct?

Answer
Hi Eric,

You stated "the ball got away".  If it got away from the 1st baseman attempting to tag the runner it is a 1 base award.

If it went out of play on the throw from F4 it is a 2 base award from the last base touched at the time of the throw (3rd base). The direction of the runner has no bearing on the award.  The umpire was correct if this was the case.

Just a little more info because I've got a minute....
r1 on 1st.
deep fly ball to the outfield and r1 is running.  
Ball is caught and r1 is between 2nd and 3rd.  
Fielder throws the ball and r1 now heads back to 1st to tag.  He is between 2nd and 1st when the throw goes out of play.  The award would be home because the last base touched at the time of the throw was second.
With a dead ball he must be given the opportunity to go back and retouch 1st.

Mark