Confronting stolen valor situations in person. How would you handle these kinds of situations?

I've never called out a fake wearing a uniform, but I have called out a higher ranking individual talking and walking on a cell phone... Politely, of course. I said, "Sir... Did you know that it was against Post regulations to walk and talk on a cell phone?" He said, "Yes, I am aware." Then I said, "All due respect, sir, but if you are a platoon leader and you expect your soldiers to follow your footsteps, like every officer most likely wishes, then maybe you should lead by example, sir." Instantly got off his phone. I was completely nervous, but still. How should my higher ranking soldiers/leaders expect me, or others, to follow the rules that s/he doesn't follow in the first place? Total Hippocratic. I was only a fuzzy patch then, in civis. But I felt like I was doing the right thing. Plus, I was annoyed by seeing this as well. I get reprimanded for walking and talking, why didn't he? Who knows if he continued to talk and walk, or if he just started to squat and talk. Being an MP, our Drill Sergeants informed us that correcting other soldiers in a polite, military manner is the best thing. This vet, however, did the right thing. I also believe in public humiliation for doing a crime, like they did back in the 1600s+; but this man should also have been incarcerated for impersonating a soldier. To civilians: if your going to be fake and put on the uniform: Do your fucking research first! Better way to NOT get caught, and to piss me off! I hate it when I see people wanting to be a soldier, halloween is a different story... But still. I worked hard to wear this uniform, I didn't cry alligator tears through all the pain, and misery, and the 'Dear John' letter for NOTHING. If you wanna be a soldier 'for a day'... Be a soldier for 6 years, THEN you have the privilege to wear the uniform that BRAVE and TRUE soldiers bled and died in, not just because you can order shit online or go to the local Surplus store.