Just because Tadashi's currently alive and well doesn't mean that a mistake wasn't made. It doesn't make the suffering that everyone else went through invalid. Callaghan's pain doesn't void the pain of others.

He chuckles a bit, absently bending the brim of his hat this way and that as tries to keep things light.

"I've had some things to take care of at home."

Slipping back into life with Hiro and Aunt Cass, for one. Convincing Hiro to let his big brother out of his sight once in a while, for another. Then came convincing the necessary organizations that he was who he said he was...

What a mess.