They can say anything they want. They hold all the power. This will never change until enough people take matters into their own hands, as the system has been compromised.
we should always be asking: is this the only way you can prove the accusation? just because it would make LEO life easier - that's not justification for violating the constitution.
an consider what this case teaches us: clean up your devices before you cross a border. how does that even help the goal of law enforcement?