Sorry for the late comment but I ran into @T Bacus today who let me know this thread was out here.
I was the RO. I have been competing in USPSA or 3 Gun for the last 15 years and have been a USPSA CRO for at least 13 years.
If anyone would have described what the guy did I would advise them it was a DQ, and frankly it didn't occur to me that someone could turn the wrong way and not be in violation of the 180 until I saw this guy.
He absolutely turned the wrong way and I was off to the side, at about 190 degree mark by the fence, so I had a good view of the angles.
As he turned I clearly saw that his gun was straight up and down and he had it far enough out that he didn't look to be sweeping his feet. It was almost like the whole thing happened in slow motion but every time I replayed it he didn't point it up range. Again, I wouldn't believe it if I didn't see it, but I know what I saw.
It took a conscious effort to not stop him. I allowed him to finish the stage, unload and show clear, and then I took him off to the side for several minutes to explain everything that was wrong with what he had just done and why he is very, very lucky to not have been stopped right then and there. I also found the MD and explained the situation to him. He agreed with my call (or lack thereof) although there was much shaking of heads while discussing.
The shooter was allowed to continue, but ironically I was forced to DQ him on the last stage of the day when he very clearly broke the 180 while trying to dump his pistol in a bucket that was up range from the shooting position.
It certainly made me reflect on the previous call. I still think not DQing at first was correct; however, he clearly was not aware of his muzzle and it caught up with him.