If they are a legitimate user of the other agencies systems, relying on information from a scanner hobbyist website should not be required and would be negligent to use it for programming radios.
If people rely on the radios, getting it from the source is the correct way to do it.
Memorandum of Understanding should exist between the agencies, this is usually signed by both chiefs/head of agency. A simple phone call would answer the question and assure you are getting accurate and up to date information.
If there isn't a valid MOU, there should be. If he has authority/authorization to be on their channels, this should never have made it to a hobby website. If they don't have authorization to use their channels, then that's an FCC violation and runs against common sense.