Inadvertant whistle

[PSU213]

Thank goodness no one on our crew had one in our latest game (or yet this season...knock on wood), but this discussion came up during our pregame:

I was saying, if you have an IW, blow the play dead all the way, and own up to it (no argument from anyone so far). My next statement was, don't mirror a whistle, because that could have come from the band, a fan, etc., and now you would have killed a live ball. The R then said, no, it does not matter, the band whistle would be an IW too that ends the play. I did not pursue it at the time because it was the pregame and I did not want us to get too far off track. So, I now bring it here...is the band whistle an IW that kills the play, or do we let the play run and tell the appropriate 'authorities' about it?