I know that for undergrad, it was possible to "appeal" a decision. I actually had a friend who did this at UBC, and ended up getting accepted after his appeal. Ironically, he ended up not going there anyway.
But I don't know if law schools have an appeal option. It might also only be restricted to public schools.
BTW, I am surprised you got rejected with those numbers. Gonzaga is trying to bring their scores up, but you still seem well within their range.