Ventura was UDT, technically not a SEAL at the time (UDT became integrated with the SEALs later in the '80s), and never saw combat. He also got the hell punched out of him by a real SEAL after he told that SEAL, who was attending a funeral wake for a fellow SEAL killed in combat, that he "deserved to lose a few"
I don't know why Ventura claims to be a SEAL and seeing combat, but he does. Becoming a UDT member was certainly no picnic and prestigious in it's own right but Ventura is clearly a tool. Never have like him...