I'm surprised Benno didn't put two and two together and called out the fact that Bart shouldn't have reincarnated since he left him to die from the wound without any treatment. He should know Hiroki is Glen by now.
I think he knows, or at least strongly suspect, but isn't pointing it out to Hiroki... yet. But his tone when he address her as "Bart" is very much mocking.
(I also strongly suspect that Minami figured it out too, but also didn't reveal it yet)
Also, remember how neatly Kumeta-sensei changes our feelings about those guys. There was time when even Midou was kinda "bad guy" for not wanting to work with Minami, then whole arc with Ootomo/Carlo who was a bit crazy uptight priest. Then Nishina, oh many still hate him, but his edge is definitely softer now. And now... Kikuchi. He's hard to grasp. But he doesn't seem illogical. And we know literally nothing about the past of "special agents", but their connection to the spirits is very weird and probably involved some brainwashing or dark stuff.
Ashley also was stabbed and "died" and... reincarnated. So Kikuchi has no way of knowing if Bart wasn't finished off with magic, so he could reincarnate.