No, it is not appropriate.
Chap 2, Sect 1, para 35:
"Reserve Force (Class C excluded). Members of the Reserve Force shall not wear a uniform except when:
on duty, or proceeding to or from their place of duty;
attending a military function or ceremony at which the wearing of uniform is appropriate."
As the CIC is a sub component of the Reserves, the above rules would apply. Note the word shall; as in not optional. Further, considering that when wearing the uniform, Reserve members are subject to the Code of Service Discipline, this member has exposed himself to potential liability under Sect 83 of the NDA, if not more. A Reserve member does not have to be on duty to be subject to the CSD.