Why would anyone be surprised by the decision of Shawn Sant in the Zambrano case? The law is very clear in Washington state, and Sant has sworn to uphold the law.
This is not some vast government conspiracy. This is a case where police officers and prosecutors are and have been familiar with legal standards which the public may not be.
If members of the public object to that result, the only reasonable way to change it would be effective lobbying for a new law. Laws change constantly and police officers would adapt.