I think you might be taking some of the ‘Chuck Norris’ type legends surrounding special forces a bit too seriously there. I have heard many stories of soldiers from extremely crack units over here (Paras and Marines) in Britain being killed or put into intensive care through nightclub brawls with local chavs. A mate from Hereford even recalls a local newspaper reporting that an unnamed SAS guy was put in hospital through a night-time attack by a gang of local thugs. Nobody is invincible, and these people weren’t even attacked by people with the training and motivation a jihadi terrorist might have.
I know the incidents you speak of but fighting hand to hand is much different from facing an equipped SF member.
Show me a single story where an elite SF member was killed by civilians while armed.