Did you notice this?

[Seal Evil]

He does not.

Yes, he does.

SCRIPT: (thanks to this)

Cloud: "At least tell us your name."

Unknown: "I was with... the Shinra Manufacturing Department in
Adminstrative Research, otherwise known as-- the Turks..."

(The PLAYER names Vincent)

"Vincent."

Cloud: "The Turks!?"

Vincent: "Formerly of the Turks."
"I have no affiliation with Shinra now."
"...And you?"

Cloud: "Former Shinra soldier, Cloud."

Vincent: "You were also with Shinra...? Then do you know Lucrecia?"

Cloud: "Who?"

Vincent: "......Lucrecia."

(Cloud shakes his head.)

Vincent: "The woman who gave birth to Sephiroth."

Cloud: "...gave birth...?"
"Wasn't Jenova Sephiroth's mother?"

Vincent: "That isn't completely wrong, but just a theory."
"That lady was Lucrecia."
"She was an assistant to Professor Gast of the Jenova Project.
Beautiful... Lucrecia."