Having experience taking a wide variety of poisons and tinctures to try and induce madness (before finding the actual solution of crazy dead mouse juice), Herbert's behavior isn't exactly foreign to Strange. He doesn't peg that it's specifically withdrawal, but he remembers feeling and acting the same way when coming down off of one of his madness attempts.

Something odd's going on here. And, to his credit, Strange's utter fury softens a tick.

"Then I should be top of that list," he mutters, more to himself than to Herbert. After all, he practically gave them his consent in a metaphorically gift-wrapped box. "There's got to be something more than that."