When Nick is initially shot after helping Jo Elliot, he is running away from the rival mobsters and presumably is shot in the back of his shoulder. After they escape, he clutches at a non-existent wound on the front of his shoulder. Later, when he is treated by the gangland doctor, it is the top of the shoulder that is dressed and bandaged.
Toward the end Jagger's Capper character got attacked by 'Bill' the dog and Nick. During the short scuffle, Jagger's hat got jarred a bit and knocked off. The first jarring showed something under the fedora. He fell back and hit the dirt, then the hat came off revealing a full head wig flopped forward hair side downward showing the bald pate. should have been cut. very obvious. No comic mention either prior or after about the rug.