Chekov's glad she wasn't with him. The images he saw would probably put her off space travel for a lifetime.

Engineering falling apart, the sound of people screaming as they're spaced or the ship collapses around them. It's not a memory he'd want to give to anyone else.

"I am glad you are safe as well."

Even if he's concerned that she might've encountered the same things he did.

"Fighting ancient evil in a bottle-world is not as fun as it sounds."