Given the highly structured and scheduled nature of work at the company, it sounds like what OP was asking was, how to wrangle HR on the necessary accommodations. They did well, IMO.

I do think the employee made it harder with the drip-drip-drip nature of the requests, which seem to have added up to a series of exceptions to the established norms, rather than being forthright in the first week or two after starting. I wholly empathize with and understand why the employee did that, but that approach sets up for a very stressful situation where little bombs are occasionally going off for the manager and disrupting long-established (for good reason, in the case of international meetings) routines.