Although Soohyun has not realized it, she was doing really good at this point. Even though she slightly lost her control for a second, he can feel her emotions at this moment and could sense that she was distressed regarding the entire thing.
The only reason he could discern her current emotions was because of the effort she was putting into this, and he gave her an encouraging smile.
He let that claw go through his chest because he knew that would motivate Soohyun further. However, seeing how she was panicking further at it made him rethink about it.
Nevertheless, he was well aware that Soohyun did not want him to be dead, and he wanted her to use that will of hers as a strength, not a weakness.
Han Minhyun clearly noticed how Soohyun was attempting to calm her emotions down at this moment, and he softly kept patting on her back, knowing very well that she was feeling all of that. He was well aware of the affect his encouragement had on her.