Steve - so you are implying it's a matter of timing as to when the runner or B/R was put out?
On the double play ball, the time between the out being made and the retired runner being hit with a throw is short enough that the runner didn't have time to react, while in the OP, there was enough time between the out that the B/R should have stopped running? Is this one of those judgement situations that we get the big bucks for?
Not trying to put words in your mouth, just trying to understand your position. I'm still not convinced there is an interference call here.