No one sees him clearly enough that they're sure he saw him appear, as opposed to falling. Though it's not quite obvious from where he fell. 

A plump balding middle-aged man in a tailcoat is the first to do something. - well, a couple of other people pulled out their phones and are presumably calling emergency services, but the first person to do something which isn't that. 

"Young man," he says, "Is that the sort of injury that you're going to want medical treatment for?"

"- yes?" mumbles Kyeo. Wow, he didn't know head injuries came with the impression that you were suddenly speaking a foreign language.

"I assume but am not confident that someone is calling medical assistance for this young man!" he says loudly to the passersby. 

"I'm calling, I'm calling," says a woman. " - yes, it's a medical emergency. A man looks to have a head injury. I don't know. Yes, he's talking. No, he hasn't stood up." And to Kyeo, "What's your name?"

"Kyeo Sebe Luk."

"Kyeo Sebe Luk," she repeats faithfully into the cellphone. "Kyeo Sebe Luk, do you know where you are?"

"No."

"He said 'no'." Pause. "And do you know what day it is?"

"In what calendar - I'm not sure -"

"He said, in what calendar, I'm not sure." Pause. "The emergency response person says that might be a very serious head injury, and that I ought to stay here until the ambulance arrives, which is inconvenient because I'm going to be late to work."

"...you could ask someone else?" he manages, but he's then going to pass out.

When he wakes up it's in a perfectly nice hospital bed in a bland beige room with framed nature photography where one might wish there were windows. There are machines attached to him. They are beeping softly. In the corner of the room, on a barstool, is a different woman in medical scrubs. "Oh," she says, "I was hoping you'd sleep until I was done with my charting. How are you feeling?"

"My head hurts," he says.

"What's your name?"

"Kyeo Sebe Luk."

"Where are you?"

"...it looks like a hospital. I don't know what planet."

"Well, I've never gotten that answer before and I don't know what it says about the seriousness of your head injury. I'll have to call in Dr. Briskel and he hates being paged." She pulls out an electronic and presses some buttons. "Do you want anything to drink?"

"No thank you."

"All right, then, I'm going to go pee and then complain about Dr. Brisket in the break room, the call button's there if you need it."

...Kyeo has a head injury and should just assume all his bewilderment is due to that.

Dr. Brisket comes in a little while later, sniffling grumpily. He wants Kyeo to squeeze his hands and follow a light with his eyes and tell him how many fingers he's holding up. He wants to know the last thing that Kyeo remembers from before the accident.

"There was an alarm going off in my ship."

"In your...ship? You were on a ship, or near one?"

"In a ship. The Five Virtues."

"You have a cracked skull and a subdural hematoma," says Dr. Brisket, "It seems to me that you might have quite a lot of memory loss, because you were found on the streets of Denver, and there aren't any ships in Denver, or particularly near it. And it seems to me that your injury likely was not suffered on the ship, because it's quite fresh. In light of all that I'm obliged to call the police, and let them know to investigate whether you were hit over the head with a blunt object as a deliberate assault. They're a lazy bunch down at our precinct station, but they'll be here in a couple of hours, and by then my shift will be over. I'm going to tell the nurse to give you more pain medication, but not enough you fall asleep, because then the cops will chew me out for wasting their time."