He reports the floor falling away in real time, then insists nobody warned him.
One of the voices that fills Carl's chat the instant the The Emergency Escape Tunnels open. His report is the clearest account anyone gives of the mechanism: a round section of floor disappeared in the middle of the station, fell away, then shot up and out of the hole, and the octopuses are pouring in — falling into the room, but from below, human sized now, and they just keep coming.
His follow-up is what stings. Told by Gwendolyn Duet to fall back to the train lines and hold the choke points as the bomber guy said, he replies that Carl did not say it would happen this bad — and when she points out that this is literally the exact thing he warned about, answers "fuck you bitch." Carl sees several iterations of the same conversation scroll past, and feels a short-lived pride give way to disbelief that people could get this far and remain such idiots.
A crawler at a stairwell station, reporting the collapse and blaming the warning.