Or, it could be that DCasey got his information from CINDY, who got it as a result of privileged communications between KC and JB. Notice Cindy and JB are awful chummy lately. And, CINDY said that she "had someone look at that area" already. I am thinking that the breach of privilege, if there is one, is actually JB giving the A's information. Even though they are her parents, they have no rights to KC's privileged communications with her attorney.
When the tape stopped rolling in DC's interview, he may have said "CINDY" told him not to call 911 (after her bad experience with that

) and the reason he was worried that it might be privileged info is because she got it from Jose. I think if DC got it from Jose directly, he wouldn't "wonder" if it was privileged, rather he would know for a fact that it was.