Some is not required here. Put clothes on and Put the clothes on are both accepted. English some has the role of a/an here, not the role of 'op.
Compare with Some guy told me the bridge collapsed. That's the same kind of some just emphasizing that it's not any particular guy. You'd never translate that with 'op as it would imply some quantity of men, not just the one.
I might express some guy in Klingon with loDHey -- not that I'm uncertain that he was a man, but it might convey the same dissociation "I don't know anything about him, I didn't verify anything about him, for all I know he's a robot, he's not the point."
You're spot-on with 'op not being right here, but I wouldn't use -Hey this way. loDHey vIlegh means I see someone or something that I think is a man, but I'm not sure. It doesn't mean I saw a man but I'm not really sure who he is. -Hey just tells how accurate you think the noun you used is.
loDHey vIlegh I see someone, maybe obscured by a mist or darkness, maybe someone whose gender I can't readily ascertain, maybe I can't tell if it's a real human or an android. Maybe loD isn't the correct noun, but I think it is.
As I said, for all I know he's a robot, or a non-gendered person. I'm not verifying anything about him.
But I understand your insistence on restricting it to literal uncertainty about whether it was a man. In fact the English usage some man is informal enough to have disputers, so it's a stretch in both languages.