Ah.
So Sasuke had experienced his first clean sweep, no wonder Obito was so quiet.
"It was good that you went with him. No one should have to deal with that alone.."

He considered quietly for a moment, mulling over his next words.
"..But why this sudden regret? You assisted him in what needed to be done to protect the village, to keep you both safe..I don't see where this doubt is coming from."