Currently, the handcuffs aren't damaged when you look into the air and right-click, due to the way events are handled. There's no event specifically triggered by pressing the "Use Item" keybind alone. To resolve this, a Network Message (e.g., RightClickMessage) should be implemented, which is consistently triggered whenever the "Use Item" keybind is used, ensuring that the handcuff's state is properly updated regardless of where the player is looking.

At the moment handcuffs aren't being damaged because that doesn't seem to be implemented. However, it can easily be added by implementing HandcuffItem#use, no network messages required.