Her assumption that he might have been the one to betray the Sanctuary isn't unreasonable, given what she knows of him. But the accusation is also not something that he's at all inclined to tolerate. Unsurprisingly than, a flash of anger crosses his face, and when he answers it comes out in his voice as well.

"What point would there be in me betraying you?"

Admittedly, he doesn't have any idea of who might have, and only a very basic idea of when she might be from in the timeline, which mostly boils down to having a decent guess as to where she's not from. And even that is mostly based on what little she's shown him so far, and that primarily through how she's reacted as opposed to what she's said.

"And I'm hardly responsible for you being here, if you were wondering."

He can't even teleport at the moment, and even if he could and had brought her here, he wouldn't have seen fit to drop her off in the fountain on his way in, when he could just as easily have set her down on solid ground besides. And likely would have, given that a water landing would have involved him also having been in the fountain.