I will leave it for Tug to chime in but it was my understanding that one of the foundations of co-management is timely exchange of information. It used to be a requirement of agreements; you must notify the other side of any opening.

So, did Tulalip let WDFW know that these specific people had been authorized an additional day? If not, then WDFW must assume it is closed unless the new rule is that tribal members are free to fish or hunt at any time and place that suits them.