In this instance the security personel were correct and it's my personal view that the captain should have gotten a bollocking(how do you spell this?) from his boss. i think he could graciously accept
his mistake rather than go into discussion on this instance.
I beleive most airlines have in theire ops manual stated that indeed he needs to wear his id
visible when in uniform etc...?
(This however does not mean i like the way some people perform theire duty's as security guard, but as long as we all swallow this inadaquate way of doing business we'll keep on getting abused as flight crew
)