...You have 12 years on BB though, so if you first upload good evidence of your own BB promotion, you should have no problem in getting second (even third) degree on your BB verified based on time served, which would also validate your student's BB.

You are stated as the promoting instructor in at least one other BB users profile, but you have only claimed having the BB without degrees here, which invalidates his BB claim (based on IBJJF equivalent standard on who can promote to BB).