He wouldn't have. Bush was within his allowed time for a physical - he had until his birthday to comply - plus I don't believe he was where he would have been flying - they didn't have his plane.
I've read reports that the deadline was the last day of his birth month rather than his actual birthday. From gut feel, that strikes me as more of a 'military-thinking' way of doing it.
I'll try to find a link to the story that had that info.