The Doctor realises quickly that the TARDIS isn't exactly unaware of something going on, beyond the mysterious rift activity.

"I can't read this," he tells her, looking at the monitor. Still, reassures her, they'll be fine, hang in there, he'll fix it. He's not sure how, but he will. Maybe her translation circuits have been knocked out or something. Only no, that shouldn't really affect her ability to show Gallifreyan, should it? He tries to ask her what's wrong.

It hasn't occured to him yet that the fault might lie with him.