Absolutely, I think this is exactly what happened - "It all goes to black", that's what they discuss with Bobby on the boat, about what happens when you die. There was a guy in the restaurant, who walked in the toilet, behind Tony, that guy was a nephiew I think to some guy Tony whacked. So after all this, I think Tony died, the guy from the toilet shot Tony, and all go to black. There was no gunshot sound, because the bullet is faster than the speed of sound, so Tony didn't heard it.