I think I understand; you're mixing two legal terms - probable cause and reasonable suspicion, into reasonable cause. That's where I was getting confused. I agree with you that the modern legal trend seems to be merging probable cause and reasonable suspicion, seemingly finding that reasonable suspicion satisfies probable cause. It does not.  Waiver of rights is a real problem. Police have developed some very effective techniques to get people to waive their rights. The only solution is to educate people about their rights.