This is a biju fight? Goodness, I thought Rakudo was just coming for a stroll.
Anyways, Nathan, sometimes people assume that the other is going to disagree with the judge; so rather than wasting time waiting on the verdict from the judge that will be argued, some just cut to the chase and post here.
The sensory barrier marks known allies and known enemies, and has a mark for unknowns. Now, if we're going Rakduo-Cmage here, then Cmage has visited Konoha before. He and Kayenta both had a somewhat fireworks show, but I believe that was ignored/voided. Since that was so long ago, I have a hard time recalling exactly the fate of that.
To my knowledge, Cmage's arrivals in Konoha normally would not trigger too many issues, since other than some wild hair moments, people were pretty tame.
Now, I believe that Yujo could potentially do what he did, if Cmage was an enemy. However, Rakudo/Cmage is a Mist shinobi, and currently, we are allied with the Mist. Since Cmage did not have much of a record for being abrasive, other than his doings outside of the village (many of the biju fights, unless finished, really can't count) then he would not have appeared as an enemy on the radar.
Maybe unknown, maybe ally, but not enemy. Yujo would have had reason to listen in on him, and so he did. So, he decides to peek out the window and, after seeing Rakudo walking the chakra hound and hearing him speak of biju hunting, he decides to Kamui him.
Rakudo is walking towards the Hokage Office; he has not yet reached it, not even in his reply post. The activation of byakugan and then dodge due to seeing Kirk underground. Kirk went underground after making his announcement for war on Konoha and speaking with Yujo. Rakudo reposted his entry post, which was going on during the discussion.
So, Rakudo is walking down Main Street, Kirk leaves the office, Yujo catches Rakudo's biju hunt chatter. Walks to window, aims, fires. Activating the byakugan would have been uneeded to catch Yujo, as his movement and chakra usage probably could have been noted by the sword, but Kirk was going in for theft.
So we presume Kirk went more or less straight to the walking sword, then he would get there around the time that this Kamui business is going on. If Rakudo goes forward to save his blade, then he would be moving in reaction to both attacks upon his party.
So, as Kage said, is Rakudo fast enough and to dodge the Kamui? Probably. Does Yujo have the intel to want to attack and to attack Rakudo? Well, if him hearing him talk of the hunt holds water (which I think it does if Ototon is the reasoning) then I'd say yes.So the fight can move on to Empty Town now, yes?