Would an E9 comply if ordered to attention by an O1?

Yes he would; and the o-1(small o) would NEVER make that mistake again. Just a personal view point from a career E-3.

Sometimes, very rarely, it is the CSM out of line, way out of line. And usually the sign of some pretty toxic leadership. When I was a young O-1, I came upon a SGM (not a CSM but still an E-9) with two of my squad leaders at parade rest screaming his head of in an unprofessional and undignified manner. I approached the SGM and asked him to step away for a second to tell me what was going on. He then tells me he doesn't have time for "my ass".

That was when I told this piece of shit "to get at attention when he talked to me" "he was welcome to call my chain of command" and in 30 words or less tell me what his issue was. Seems this his personal crusade against improperly bloused BDU pant legs, and having two junior NCOs stand at attention while he berated them in public was his idea of corrective action.

So yeah, O-1 locks up E-9.

Has too it depends on the situation if a captain / colonel walks in or a flag officer if the 01 calls for attention you snap to it as i said it depends on situation

tgechnically yes because of rank but we all know better.

I've seen it a couple of times. It's always pretty hilarious except for those rare kids who didn't quite grasp the concept. A squared away CSM is a powerful thing.

The only time that I've seen a Senior NCO deserve it was when the guy was on ROADs. Had a few of them. Even those guys, though, would rarely be so Roadied out that they'd take shit from a brand new 2LT.

2LT out ranks a CSM....

I have seen for myself an E7 put an O1 in his place. And when it was over that Smoke was walking around like it wasnt a thing. He had an ora around him like he was the next best thing to Jesus.

Had an O-1 tell other officers that my Senior Chief worked for her. She had some words for her and put her in her place lol.

He has no choice ... its in his oath of enlistment!

In the Corps once you hit Gunny I see nothing but respect from enlisted and officers as well. Those stripes come with years of dedication and hard work. From E-7 to E-9 are areas of RESPECT by all and admiration by enlisted. Semper Fi!