During cross exam of State's witness, defense attorney suggests in his question an alternative theory or explanation for fact to which the witness testified on direct. It is my understanding that the attorney must have a "good faith" basis for believing the theory or explanation is true, but may properly assume the existence of facts not in evidence.

Suppose, however, he does not have a good faith basis. Or suppose no evidence is ever offered in support of the assertion. Suppose only the defendant would know whether the assertion is true, but he chooses not to testify. Is an objection, e.g., "no foundation", proper? What other objection(s) would you raise or think should be sustained by the court? How do you challenge the "good faith" of defense counsel? Maybe by requesting a bench conference?

Suppose it became evident defense counsel violated Tex.R.Prof.Conduct 3.04(c)(2) or maybe 3.01 or 3.03? What should be done about that? Is it possible for a defendant to waive the privilege of prohibiting the prosecutor from referring to his failure to testify? Are you not entitled to explain to the jury in argument that the defense counsel's suggestion not only was denied by the witness, but also fails to raise any reason to doubt the witness's account because not based on any evidence-- even though that evidence could come only from the defendant?

What I have tried to describe seems to happen in some form quite often (typically the witness being impeached is the victim). But, I must confess I am not sure how to best prevent it from hurting our case. Given the reluctance of trial judges to limit defense cross, what has worked for you?