I think you're right, and I certainly hope they did hair and fingernail analysis.
From what I'm googling, that may be the only way to determine if he was poisoned with arsenic, since it leaves the body after a few days, but if done within 6 to 12 months those particular tests can help.
You would think the docs would have tested for that, wonder if they did.
Will he ever revert back to his normal looking self or will he appear this unhealthy from now on?