Actually Tobbis didn't say that either kid was in there.
If the two kids are in there
That If is a pretty big thing. It could be one of the kids, both the kids, neither of the kids. He tracks matrix signals, not bio-signatures. It could be very well possible one of the two kids left their commlink in the manor. It could be that both kids are still in the manor and one of the manor personnel is leaving. It could be someone who wasn't around at the time when Daddy did his astral search, came in while we got in there, and is now leaving.
Hence why he's also alerted all the runners that there was movement going south, and that he doesn't know what it is.
But its also why he's doing another matrix perception on the thing. Right now he's moving at his highest speed, being VR in the matrix. Even if it moves out of normal tracking range.. His Satlink should keep him able to keep on it.
As far as opening doors and the like, I don't think he sees any locks/cameras/doors to open via the wireless matrix. Maybe they're all throwbacks, or they're running silent and he's missed them.