Of course that is unreasonable. I don't think it was meant to be taken literally, but as advice recommending that as a suspect or person of interest one generally shouldn't assume that law enforcement folks are on your side.

(I have a lot of respect for the police: they accept a lot of risk to try to ensure a civil society in exchange for not a lot of reward, but there's little doubt that if they see themselves in an adversarial relationship with someone they are willing and able to mislead or misdirect that person in order to accomplish their aims. There is a reason that the Miranda Warning became a legal requirement.)