"I will go with your recommendation, then," he says. "...Well, anything but fish," he adds, just to make the point.

He lets the other subject drop; Near knows virtually nothing of the Doctor, and little of Martha, really, but from the little he does know, he can't imagine that the man would let her get hurt...

Still, there's no point in saying anything, especially considering the fact that Ianto is obviously better-informed, and would be unlikely to take an irrational dislike to anyone. For Martha's sake, though, Near hopes he's wrong.