Thank you. I have always wondered--as a non lawyer--why it was allowed by state courts to bring in decisions of other state courts where no cross border issue was involved, such as water rights on the Rio Grande. But it seems to the discovery process is so umbridled, and our law so poorly codified, that everything is gist for the mill.
In my experience (limited), decisions by other state courts are brought up mostly when there are no closely relevant decisions in the state the court's in. They don't have real precedent authority, but will be taken seriously.