This is true but im not sure about the time scale i.e what you have or haven't served.
But what i do know is from a Royal Navy / Royal Marines point if you have done a BOST or OST which includes firefighting, dunker drills etc etc then you can go through the civvie @ H.M.S. Excellent or maybe even Raleigh where ever you done the training then they can send you them for free and they have no period of expiry this is great but companies may ask when you did it and if your reply is "10yrs ago" then you could be forced to get a more unto date course under your belt.
From lads i know who have done it they have had no probes, + it doesn't matter how long you have been out as i only apply last year for it and i had been out for over ten years and i was still on the system.
Be aware if you failed any modules or didn't complete the full course then they might not send you out the certification, hope this helps