Like a soup sandwich...
Ain't that the truth.
I've seen a few situations like this in my time in this sport, but it's always the shooters responsibility to maintain safe control of their weapon (there I go again, pissing off the NRA again by calling it a weapon. . .oh, well). That includes some dumb-assed RO walking in front of them.
And that's as it should be.
The shooter is ALWAYS responsible for their weapon, and where it's pointed. No question. Regardless of all else that's been said, the shooter DQ'd themself in this instance. But I hate to see so much asshatery involved in what should have been a simple situation. Unload and Show Clear, and let some RO see to the problem downrange.
Yeah, I've had a bunch of shooters stand on the line with a loaded gun in their holster while an errant popper was reset, or other range equipment malfunction was attended to, but I sure as Hell wouldn't ask the shooter to pull their loaded blaster out as part of the remedial process.
There just isn't a process within our ruleset to appropriately punish the dumbassed RO at that moment. I can't think of proper wording for such a rule, and I guess no one else has been able to either, or it would exist.
It's sorta like one of those heart-breaking ASPCA commercials where you think, "That shouldn't be that way". . .but it is.