Similar thing happened to me today.
I was playing 9-ball with my normal Sunday opponent and I FIRED an 8-ball hard about 8 feet down the long rail and hit the end pocket dead center.
The only way to get on the 9-ball was to hit it hard and draw the cue ball three rails for position. I hit the ball better than Earl Strickland and got PERFECT position on the 9-ball about two and a half feet from it and straight it.
I then shot the 9-ball in for what I thought was a win. My opponent then says, "the ball came out of the pocket and went on the floor". At first, I didn't know what he was talking about. I thought he meant one of the balls came out of the track and fell on the floor, which happens quite often on the table we play on.
What had happened was that I hit the end pocket dead center with the 8-ball and it went over the edge and onto the carpet without making a noise. I knew as soon as I hit the 8-ball, I had hit it perfect, so I looked at the cue ball to see if it was going to take the English off the rail and I didn't see the 8-ball go over the edge.
There was at least 20 or 30 seconds before I shot the 9-ball and he didn't bother to say a word, until I had made the 9-ball.
With the rules, he would have had my position straight in on the 9-ball and the 8-ball would have stayed down, so I don't know why he didn't say something until after I made the 9-ball.
He has a tendency to try to pull everything in the book to win even if it borders on being unsportsmanlike conduct. I have to constantly remind him of it. He is used to playing young guys he can beat all the time and he gets a bit cranky when you spank him a lot.