What is the test for improper prosecution of a defendant's right to counsel?

"'The right to counsel is so basic to all other rights that it must be accorded very careful treatment. Obvious and insidious attacks on the exercise of this constitutional right are antithetical to the concept of a fair trial and are reversible error.' [Citation.]" (People v. Fabert, supra, 127 Cal.App.3d at p. 610.) Here, the prosecutor, during rebuttal, told the jurors that defendant asked for a lawyer because that is "something that people ask when they know they've done something wrong." In other words, she argued that defendant's invocation of the constitutional right to counsel was a reason to find him guilty. Although there is no evidence that the prosecutor acted with ill-will (at trial, defense counsel expressed her belief that the prosecutor did not intend to prejudice defendant), this argument by the prosecutor was "flagrantly improper." (People v. Schindler, supra, 114 Cal.App.3d at p. 189.)