When Billy is by the TARDIS Sally gives him the phone number. Then you see the TARDIS with weeping angels around it and Billy goes to them and blinks then he is caught.
But if the TARDIS was alive then the angels should have stayed stone because the TARDIS can see them.
Even if the TARDIS could see, the outer walls prevent the living part from seeing outside. The TARDIS does have a scanner, which could be considered "eyes", but it can only see in one direction so the other sides would allow the angels to move.
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