Theodore wished so hard that he had an answer for that. He really didn't know, for the exact reasons that Barty was thinking.
"Unfortunately, no," he said, wishing he had a better answer. "But so far, he's only made progress. I'm very hopeful that he'll regain them all, even if it takes some time." He smiled a little. "Hopefully not too long. I'd like my mentor back, too."
He had always liked having the infirmary to himself when Rosier was gone, even though it was more responsibility. This was different, though. He didn't want Rosier to stay way indefinitely, he had more to learn from him. And he had saved his boss's life, which he hoped would repay the damage he'd done to the trust between them.