Vincent and Robert’s reactions immediately make Hikaru’s heart sink. He’s been convinced for quite some time that his projection would show the worst things imaginable, and he’d even invited Vincent… So seeing them like this comes close to confirming his fears.
But Kaoru completely flips that on its head. ‘Lighten up’ is probably not something even Kaoru would said if there had been anything truly visceral in there. So… Did that mean things weren’t as bad as they could have been?
…Thinking about it makes his head hurt. He doesn’t know if he has the mental strength to even try to carry a conversation right now.

“…We’ll talk later,” he eventually gets out. It’s directed at everyone and no one, and is mostly an excuse for him to leave without saying anything else.