Strictly speaking, TBS LR shouldn't be covered by CITES since it's aquacultured by placing plain dead rock into the the TBS guy's "backyard" which happens to be the Atlantic.
But this and the orchid story goes to show that it's a crapshoot at the border. It's often up to the person you pull up to and how he/she interprets what you declare to him/her - take it from somebody who spent much of his post-secondary years slogging at YVR
Oh, and they wouldn't have arrested untamed. The worse they would do is hold the rock and give him a seizure receip.