Mine as well. Hillman also uses command - nick - command. The second command encourages stability. Remember that the dog has no idea what that nick means. If you "Sit" - nick and dog jumps or spins, the follow up "Sit" is logical IMO.
Regardless, if you have chosen to use Rick Stawski's program, I'd follow it to the letter unless I came to something that didn't work out as planned. Later in training when using indirect pressure the nick is usually sandwhiched between command such as toot-nick-toot.