The only reason that Ness does not fall into the water in shock is that this isn't the first time this has happened. As it is, she still squeaks and flails and kind of stumbles away from the railing in a small panic.

I wasn't going to, I was just thinking about it!

She looks around, searching out the person whose mind she's unintentionally linked with—her eyes linger on the qunari, but mostly because he's a giant horned person in a crowd of humans, not because she knows he's who's in her head right now.