why does cheever fear proctor when its time to show proctor the warran for elizabeth ?

Proctor is fiercely defensive of his wife because he loves her and over his own guilt from his infidelity. Proctor is a strong man and a passionate man. Cheever is there to take Elizabeth away over being named by Abigail. This sets Proctor off even more for it is in part his fault that Abigail hates Elizabeth. Proctor could easily hurt Cheever.