Not to be a contrarian, but once you earn a title you should be addressed by it. For instance, you don't call a Doctor "mister". A Master Chief Petty Officer in the Navy has earned the right to be addressed as "Master Chief." A ship Captain is entitled to be referred to as "Captain". So is an airline Captain.

Now, you probably don't want to carry your Regional title when you move on to the Majors, but when you earn the fourth stripe at your current employer, you earn the right to be addressed as "Captain".

In the case of a scab like Mr. Green, that theory might not apply.