While in Frasier's studio, Roz brings Bulldog a basket of cookies; he then asks for some milk. She rushes off to get some, but when she returns to her booth, she doesn't have any. Then, at the end of the scene, a gallon of milk has somehow appeared on Frasier's console.
Bulldog is seen dropping his coffee cup in order to hide behind Roz and turn her towards the person he erroneously thinks is the gunman. The dropped coffee cup spills on the real gunman, who is standing to the left of the counter and is looking towards the server's working area. However he has his body turned towards the door while pulling his gun.
The coffee cup then rolls off the muffin tray and onto the floor by the entry door side of the counter. In the next few frames the coffee cup is not seen on the counter then returns lying on its side. As we watch the scene recounted by Frasier later at home, we see the coffee cup leave Bulldog's hand. It seems to go over the muffins in the other direction, bounce on the counter, and then fall into the walkway where the servers work. The cup bottom is facing the gunman. We then see the scene a third time where the coffee cup spills its contents on the outside counter area over the muffins and the coffee spills onto the gunman's hand. This time the cup bottom is facing away from the gunman.
Frasier never turned around during the attempted robbery, he would've had no way of knowing Bulldog mistook another man taking out a wallet for the man with the gun.
Daphne calculates if she had a lifetime supply of free muffins, 10 a week for at least 40 years it would be 20,000 muffins. 10 muffins a week, times 52 weeks a year, times 40 years actually equals 20,800.