Its been some time.
Wow, Don't hesitate to tell your son how proud of him you are. Sounds Like a True hero in my book. Even if he never gets the chance to save lives he has already made a great sacrifice by just getting the training and skills to do a job not many could do.
My brother is a firefighter in Ohio and I got to see some of the fires he has gone into to save people and I sure am proud of my little BRO (he is about twice my size though):)