"If I ask a question, I expect an actual answer" Thaddeus stated. He noticed that she dodged his question, or at least he did not comprehend that she answered it in a different manner. He wanted to simply leave for he knew the risk of interacting with anyone. The more interaction there is, the more acknowledgment that they are human. Empathy is the worst handicap a soldier could have in Colonel Gaunt's mind. With empathy came hesitation and a whole host of other emotions to pour through such as despair, frustration, and anxiety. No, to acknowledge the humanity of others was the worst sin on the battlefield. 

"I know only two things of you. That your name is Maria and that you are a Catlyst. I only needed to know one of those two things to pass judgement to you. And yet I find myself doubting" And It was true. After listening to what General Bishop and Tiger had stated earlier, he found himself doubting. He hated feeling doubt. He tried to transfer that hatred into her, but he found himself failing. When he first saw her, his vision was stained with a target scope. Now actually being next to her, he could see that she was a living breathing human being. And he hated himself for acknowledging it. 

"I am Colonel Thaddeus Gaunt, callsign Chaplain 1. I have showed many of our enemies the burning radiance of our God . Prove yourself to the eyes of the Lord and you will prove yourself to me. Now what am I to call you? Or shall I simply refer to you as the Catalyst?" Even if he felt a tiny speck of empathy for her, he wasn't going to show it. He wanted to have at least a single shred of himself still.