It wasn't on the CBS schedule, it was originally produced just for the Australia TV market. Also appears it was all shot before the SAG strike (in May), so everything was in the can before then so even if SAG actors are in it, it was all shot before the shutdown. Makes sense since CBS can just plug it into the schedule since it is ready to go.
But it is a example of one of the issues that came up in the writers strike. The entire season is just 8 episodes. Writers complain in their strike was getting hired on to write for a series used to mean working (and getting paid for) 20+ episodes. Now it can be a lot less work and pay.