"The Other Guy showed up. Yeah, she's... She'll be okay." Because he knew that she would be. Maria Hill was a tough woman and had strength in spades - while Bruce's disappearance may have left her shaken up, he knew that she would bounce back. It didn't take away the sense of concern he felt for her anyway - which still shocked him, honestly - but she would be okay. He already knew the team would make sure of that.
"I'm sure he's fine, just-- I just need to find him. Look for him, at the very least."