Ok but have you considered:
McCree doesn’t exist in Sombra’s database because Reaper has obliterated all of his files, all of his information, any tiny little piece of evidence linking him to Overwatch.
Sombra picks up a security feed from eight years ago of what appears to be a strange man dressed as a cowboy involved in a covert Blackwatch operation. No way he’s Overwatch, Sombra, just look at him. Look at the way he’s dressed. Obviously a civilian. Ridiculous.
Sombra stumbles over an old Overwatch manifesto that specifically includes one “Jesse McCree”. Never heard of him. He must have been one of those pathetic recruits that didn’t even make it past basic training. Don’t give me that look, do you think I would just forget any of my former teammates? I’d remember a name like that. He’s probably not even worth hunting down.
Papa Reyes is still protecting his little ingrate.
The Amaris are fair game. That witch Ziegler can rot. Hell, take Jack, too, if you have to.
But don’t you DARE lay a hand on his boy Jesse.