Tony,
I would allow the action, because if you change it or add a rule to change it, then you will end up effecting far more than you intend to. Example, a guy gets picked off at first and then is hit in the back while running to first and the ball goes into the outfield allowing R1 to get to 3rd. Technically he interfered with a throw, but I think we can agree that we are not going to call interference unless it was an intentional act. I could come up with coutless other examples, but I think you see my point. Like I said earlier, I think the rules are rather clear, but I could be wrong. And that would not be the first time today.