In criminal matters, if a judge makes statements during oral arguments that clearly show that the judge has a misunderstanding of the case law pertaining to the matter at hand, can the judge's decision be appealed even if the written decision itself does not contain an explicit error?
For example, let's imagine the police search a car and find an illegal item. The defendant makes a motion to have the evidence from the search suppressed on the grounds that the police had no probable cause to search the vehicle. Whether the police had probable cause in the case is complex issue involving many different facts. Let's imagine that one of these facts is that the police officer stated that the car owner's mechanic told him that the the car's airbag system had been tinkered with, a violation of US Federal regulations. During oral argument the defense argues that the possible violation of a Federal regulation is not grounds for a search. The judge then speaks out and says that violation of a regulation is still a crime and therefore potentially grounds for search. Later, in the written decision, the judge dismisses the motion to suppress, but does not explicitly give his reasons or gives other reasons, not involving the violation of a regulation.
So, let's assume for the sake of argument that the judge made an error when he stated that violating a regulation is a "crime" and therefore grounds for local police to search a vehicle. Can the defense argue that even though this error does not appear in written form in the judge's decision, the fact that he said such a thing in court shows that he has a defective and incorrect understanding of laws relevant to the motion, therefore he is not fit to make a ruling on such laws.
So, imagine that the appeals court finds that the judge has a clearly defective understanding of search and seizure law as evidences by his remarks in court. What is the outcome? Do they remand the case to the court, reverse the ruling, or take some other action?