Is consent obtained prior to a search or seizure valid before any illegal police conduct occurs?

"A search or seizure made pursuant to a valid consent before any illegal police conduct occurs is obviously not a product of illegal conduct. A search and seizure made pursuant to consent secured immediately following an illegal entry or arrest, however, is inextricably bound up with the illegal conduct and cannot be segregated therefrom." (People v. Haven (1963) 59 Cal.2d 713, 719.) Defendant contends his consent was invalid because he was detained by a show of authority just before he was asked to consent to the patdown.