Steve knows the rules. No civilians on the bridge, in engineering, or tampering with the transporter rooms. For the most part, he follows those rules and goes through the proper channels to get the attention of the captain or his chiefs of staff. For the most part.

Steve isn't opposed to breaking the rules when the situation demands it.

He's expecting to be stopped by one of the security officers when the turbolift doors open, to get a sharp word from the captain, or to even be physically removed (or for someone to try, anyway); what he isn't expecting is to nearly collide with a walking, talking dog.

"Wh--?" he blusters, taking a quick step to the right. And then his eyes widen. "How--?!"