I’ve made really stupid jokes to people. This situation though It didn’t even sound like he was joking. The “faulted” part, is not really a “fault”, it’s literally a brain processing information. It takes time for brains to figure stuff out. You basically made a comment (perhaps out of left field?) and it took him a moment to think it through and respond. It was a rational response. Afterwords, he thought immediately about your emotions. Kinda difficult situation all around and it really does sound like he’s trying his best.