When an E-4 calls me "hey" or "hey man" knowing that I am an officer, should I bother to correct him?

When I was in A school myself and 4 other Sailors walked past a Marine Officer. I saluted they walked on by. He stopped us all Explained his rank and gave them heck ! Then he explained that if nobody teaches you You never learn. After I got out of school I needed an Officer to sign off on some paperwork and remembered where he work. I asked him to sign off for me he actually remembered me and did as I asked. So long story is yes correct them and teach them not just show off your rank.

100% yes, correct a lack of military bearing. There was a CSM at Fort Hood who always carried a ball bearing in his pocket. As a senior NCO he chewed out an motor pool enlisted soldier real bad, it was over the top. An E-4 handed him a ball bearing and told him that he must have lost it. Although he was pissed off he realized the E-4 was right and after that day always carried the ball bearing and if you asked to see and he did not have it in his pocket he would do 100 push ups.

I guess the Army and Marines are just vastly different in culture than what I was used to growing up around USCG aviation on Navy & CG Air bases and Air Force bases.
I was raised to say yes sir or ma'am to everyone and I still do to this day. However, I can't imagine any of the officers I grew up around or served with would have cared if an enlisted guy or gal they didn't work with said "hey man" while they were off duty in civies.
I think everyone should be respectful to each other. I think we should also maybe not take ourselves so seriously as well.

Yes correct him. This would never happen in the Marine Corps. True story, went aboard the USS Underwood to see my brothers ship. I was an enlisted NCO in the Marines. An ensign was addressing a group of sailors in a formation. Many of the sailors were just llaligaging. Talking amongst themselves.

I told my brother, if an enlisted Corporal or Sergeant was addressing a platoon and there were enlisted of junior grade in a formation just talking amongst themselves, there would be he'll to pay. Unsure what the formation was for, but there definitely a huge difference between different branches.

Respect is due in or out of uniform. You would not address a senior officer as "hey dude", or "what's up man". Would never happen. Nip it in the bud, if it happens to you. You don't have to be a dick about it. Simply tell them, to respect you in or out of uniform. Enough said. Corporal out!!

Outside of work as in off duty hours and out of uniform? Personally I'd likely call an officer Sir/Ma'am anyway out of respect and habit but that's just me, and there's no requirement to do so. I'd probably let that slide.

Prime Time to correct a Specialist I would make a correction by asking him to the side and explain that he is showing disrespect and if it happens again you will inform his Chain of Command. If this does not work address it with his unit 1SG Im sure it will get corrected quick lol

Yes. That's disrespectful if he knows you are an officer.

Rest assured if one of your higher ups were to overhear him, you would get reamed for not correcting him on the spot. I good friends with a many years retired Marine colonel. For years, I've called him by his first name, Colonel.

If you don't call this E-4 out as a E-9 I will call you both out .Respect is part of the military and as a E-4 he should have learned that "Sir".