What’s the proper way to correct someone when not saluting an officer?

Counsel the miscreant on what violation of ART 89 UCMJ will earn him/her.

Yes do ask politely the pfc that you would appreciate a moment and take the pfc aside,know which standard you are referring to and remind 5he pfc of this for future reference. Should your c.o. witness you not leading, it might cost you, career wise later. It's a tradition you don't uphold I'm the field but on duty at least on post you do. Many officers have earned the respect and many enlisted men have carried on the time honored greeting of respect.

I believe the comments was appropriate. When stationed at Fort Knox we had many long convoys with rank displayed on the vehicles. On the way to my lab/office an E1 faked to salute vehicles with ranks up to O.7. I was tired but saluted as appropriate . When the convoy passed I called to the rainee. He came as called, asked why no salute.. I asked his name and unit and walked off to the nearby hospital. After a few calls I called his unit and my call was tanferred up the chain of commandI reached he commanding officer who told me to meet him at the Officers Club at 1700 hrs. He looked surprised when a medical service officer with spit shined shoes and crisp khaki Uniforme showed up. He looked surprised and bought me a drink. He explained this trainee was a racial agitator and everyone else was fearful of repercussions. I assured him that was the least of my fears and he had his Sergeant Major meet me to sign the documents. He stated he would proceed with an Article 15 and it would likely be refused and aCourts Martial would follow. Much to our surprise tha “radical “. Trainee accepted the non judicial punishment. When I had enlisted I knew there would be times of fear, and you never let control you, you acted on-site of it. WaynePrice

Perfect answer. A lesson I learned years ago. Correct failures like this smartly and the kesson is learned.

Lastly, how you approach the SPC is important. Which should be carried out with the utmost professionalism and professional respect.

You were justified asking that Soldier why she didn’t salute and all service members should question such disrespect, even though at times it may be unintentional.

As a fairly new Army Reserve SPC assigned to a unit that drilled on a Navy base I was very skittish about saluting the wrong people. I knew my Army rank and how to quickly identify officers but trying to differentiate Navy officers from Senior Enlisted with the sun in your eyes, and all the different uniforms. I got yelled at by a Petty Officer for saluting him one day, the next day I apparently missed a Captain in a group of NCO's because one of them watched to see what building I entered, and I received a phone call from from him as I was standing at the front desk waiting for to pick up the keys I had been sent for. I stopped leaving the building on foot if at all possible after that when I was there during the week. (Changed into uniform after I got to work, went right out to "our" parking lot at lunch, changed before leaving at the end of the day.) A PFC may not have even been to basic yet if they are in the delayed entry program. Correct them yes, but try to avoid embarrassing them, shaming them does not help the learning process.
Eventually I did start leaving the building at lunch with some of the older junior officers and junior NCO's, they would give me a "heads up" or "you're good" when a bunch of navy in khaki was headed in our direction. Between that and volunteering with the Sea Cadets I now know Navy rank and uniforms, but as a new Specialist it was just one more thing some Sergeant to yell at you about. Officers don't usually bother to make the lives of Junior Enlisted soldiers miserable, (at least not intentionally).

No, you should point it out as humanly as possible. I remember a PFC getting reamed by an LT for not saluting him.

Major was wrong. You do have to be aggressive. You are in the military. The point of the military is to fight wars. Whatever you DO in the military is immaterial, you are all in support of war fighting. Remarks complete.

Protocol.... you need this to maintain the relationship between officers and enlisted.