It's like having a bucket of cold water poured over his head. One the one hand, Lapis gets it - she's seen him screw up, and she's still offering him support. On the other hand, somehow, she still doesn't get it. It's a bizarre contradiction, but in a way, it helps - he'd rather spend energy trying to figure it out than being angry.

"Look, Lapis, I get it. Believe me, I-" He laughs, and it's a quiet, mirthless sound. "-I can hear it. I just-" How does he say this? How the hell is he supposed to put this? "I get that you're tryin' to protect me, an' I get that I need it." That would usually be a blow to his ego, but he doesn't seem to have one of those right now - it's been beaten to pieces. "An' believe me, I'm grateful. But I don't think you understand that what you did out there wasn't protectin' me. Sans was scared, but he wasn't shootin'. You shot first; you made it violent; an' you could've killed Agent 3. I know you've got a lot of control, but you can't guarantee anything in that kind of situation. I just...I need to know that you get that."

He trusts her with his life, but he doesn't trust her judgment. It's a weird spot to be in.