"Oh, right. You didn't see me come in."

Ignoring the fact that no one saw Sombra come in, but what can you do?

"But now you know, and so we're all a bit more educated than we were ten minutes ago!"

As for the tech -- okay, some parts of it are better than a hackjob, but none of this is real custom work, which means Sombra's fingers don't even need to be at their most limber in order to dance around the firewalls.

"Oh, pobrecito. You thought that was clever, didn't you?"

Apparently Sombra talks to programs sometimes. Usually when she's gloating over her triumph.