CAS 9 lines are becoming known as "CAS briefs" know because "9 liner" has entered wider parlance as a CASEVAC request. CAS briefs can be omitted if there is an immediate threat to life and no other action is possible; those circumstances usually invoke national rights of self-defence which can never be restricted by rules and regs (that's not to say that a brief wouldn't be given if circumstances allowed).
Outside of self defence, it could be the case that a CAS brief has been given some time previously and is simply being updated by the passing of a new target position. It's not necessary to give the whole brief again. Finally it should be noted that a CAS brief need consist only of the target and friendly positions, which can be done in exactly the kind of quick verbal exchange described without any need for coordinates.