Is there any case law where the police officer changed the subject of questioning from one offence to another to avoid giving effect to a defendant's right to counsel?

This was not a case in which the officers simply changed the subject of questioning from one offense to another to avoid giving effect to a defendant's invocation of his right to counsel. (See People v. Pettingill (1978) 21 Cal.3d 231, 245, 145 Cal.Rptr. 861, 578 P.2d 108.) Defendant did not invoke the right as to all subjects, only as to one.

Defendant finally contends that his consent to search his apartment was obtained as the result of the foregoing violations, and the evidence seized [3 Cal.4th 123] was therefore inadmissible. There was, however, no violation relevant to this case or to defendant's consent to the search. "Because the tree was not poisonous, its fruit was not tainted." (People v. Mickey (1991) 54 Cal.3d 612, 652, 286 Cal.Rptr. 801, 818 P.2d 84.)