i understand what you're saying. personally, i would replace the timing belt; but i don't think there's any real risk at replacing it at say 95k instead of 90k. i honestly don't believe honda would schedule maintenance or replacement of a part right when it was due to fail. things are usually engineered to perform well past their suggested "expire" dates. servicing when recommended is just preventative maintenance (and good practice), but it doesn't mean things are going to blow up if you wait a little longer on the service.

in other words, i'm confident that he'll be fine.