Inadvertent horn :(

[JLK]

Almost the same situation regarding a horn going off happened to me this weekend at a youth tournament. Visitors are down by 1 with 1.9 seconds remaining. I hand the ball to the player for the throw-in. Just as he released the ball, the horn for the next court over sounds. All players stop but the ball ends up in the hands of a home player. I blow play dead, confer with partner and table. We decide to put 1.9 seconds back on the clock and have visitors have the throw-in again.

Well, sure enough, visitors score to win by 1. Needless to say, the home coaches are very upset by this. I explained to them that did the replay seeing as everyone had stopped (it was just a lucky bounce of the ball that it ended up in the hands of a home player) due to the horn.

As I thought about it later, I was wondering 2 things:

1. Was it correct to do the replay?
2. If it was correct to do the replay, should we have left what ever time was showing on the clock @ the time whistle was blown (in this case, time remaining showed about 0.8) or was putting original time back on ok?

Thanks, input is greatly appreciated.