As far as I can tell, no one was flaming, just telling him to be careful.
A very brief (i.e. not thorough) search turned up the following:
Colorado Criminal Code (Title 18)
18-12-105. Unlawfully carrying a concealed weapon - unlawful possession of weapons.
(1) A person commits a class 2 misdemeanor if such person knowingly and unlawfully:
(a) Carries a knife concealed on or about his or her person; or
18-12-101. Definitions.
(f) "Knife" means any dagger, dirk, knife, or stiletto with a blade over three and one-half inches in length, or any other dangerous instrument capable of inflicting cutting, stabbing, or tearing wounds, but does not include a hunting or fishing knife carried for sports use. The issue that a knife is a hunting or fishing knife must be raised as an affirmative defense.