His case may be different since he was already in and they actually have a lot invested in him. In Viti's case he is an Academy grad and I am sure they will find a suitable position for him.
I graduated in 99, there was no war going on and there wasn't a hard on to sign people up. I tore my ACL sophmore year and had surgery and was fine. They told me I was a liabilty at the time.
Special forces is very paticular because they trek through the harshest conditions for days at a time. If you have past injuries you could leave the rest of the team vulnerable and that in turn would exclude you. I just finished reading "Lone Survivor", unbelievable story about a Seal Team in Afghanistan. If you like military books, this is an unreal true story.
Tell your buddy thanks for his service and good luck.