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

Two words "fuck no"

I served with, and was mentored by numerous CSMs and SGMs (E-9s) all throughout my career. Whether as a lowly "butter bar" (O-1/2LT) until 24 years later retiring as a LTC (O-5). Only an idiot would create an incident, regardless of today or in the "old days"... I was "Blessed" to have NCOs that, regardless of the situation, or circumstances, would "train and mentor" me in making tough decisions... fairly, and "on time". In America, THE NCO Corps is STILL the backbone of ALL THE Services. I wouldn't trade any of mine, or the ones I know, for anything...

Technically, maybe. Real world, he'll no.

I believe that the call to attention should be obeyed but I also believe that the O-1 should as respect the years of service of the E-9. The E-9 I believe should request to continue the conversation in private with the O-1 and respectfully be reminded of that fact as well in case he has forgotten. In that manner there is no disrespect between ranks in the eyes of those who may be witnessing the interaction.

But on the other hand yes that Lieutenant's life will be a living hell to the day he gets it out of or he resigns

Yes that 9 should come to the position of attention when an lieutenant who is an officer commissioned by the president of the United States

Had something similar happen while I was in Great Lakes. I was in my bunk on medical with a badly messed up knee and under orders from my CPO to not put weight on it. One of the recruits saw the LT come in and called for attention officer on deck. Because of my knee I couldn't move as fast as the others and needed crutches to stand. Naturally the LT notices me not on my feet yet and starts to chew me out. Chief walks up and tells me to stay at ease until I got my crutches squared away then to stand. LT did not like that order and told my chief to belay the order and immediately orders me to my feet. So with out crutches in hand I attempt to stand on my good leg, while the LT is waiting for a proper attention. LT asks why am I not at proper attention, I tell him I am unable to bear weight on my bad leg and show him my paperwork from the hospital. He looks it over and looks at my leg, tells me to grab my crutches. The whole time this is going on Chief looks like he's about ready to explode. I didn't get to witness the conversation later between the LT and Chief, but I can imagine it did not go well at all.

Technically an E-9 would come to attention, but in reality another officer would snap that butter bar to attention.

Yes, then he we discuss any grievances with O-6 to O-8 he works for. The L T will learn the a new understanding of respecting the enlisted branch

Once witnessed a young 2LT at TBS in Quantici, call the MGYSGT that I was walking with to attention, due to an "improper" salute.....what this 2LT was not aware of, is that this E-9 was a multiple Purple Heart receipant from Vietnam. He complied, but not before he , the E-9 dismissed me. I stood back, out of my AO, and watched an education bring taught....there was much respect from that 2LT, following the discussion.