Dead ducks

I shot a couple of mallards this past saturday, a drake and a suzie. I might have killed a wood duck in a scotch double on that suzie, but it was a strange situation. Ed shot at a duck and thought he was behind it, then I was on that suzie a fraction of a second later dead bang. We both only saw one duck come to us, but after we shot we heard two splashes. I have no idea how that happened, but there were two birds down. Ed said "scotch double" a couple of times, but the more I think about it, the more I'm convinced that we were actually shooting at different ducks. Strangeness.