An edit point during the first minute sees Alan (Nicholas Lyndhurst) raising his glass to his mouth, before cutting a wide shot where his glass is being held just off the table.
When Frasier and Freddy are eating chili, Freddy's beer changes position on the table between shots.
Frasier spent eight years visiting the Cheers bar in Boston. It's hard to believe he wouldn't know how to pronounce Celtics properly.