Inflammatory questions in cross examination

Desharnais v. Parkhurst and Romanowski, 2013 BCCA 113 deals with inflammatory questions put during cross examination:

[79]        The plaintiff relies on R. v. Fanjoy, 1985 CanLII 53 (SCC), [1985] 2 S.C.R. 233, 21 D.L.R. (4^th) 321 for the proposition that a trial judge's failure to restrain abrasive or abusive cross-examination may be an error in law.  Fanjoy also stresses the discretionary nature of judicial interference in cross-examination.  Justice McIntyre stated, at 239:

... The discretion to intervene in a cross-examination must, of course, be exercised judicially. Its exercise does not rest on legal considerations alone, but will depend as well on the facts and circumstances in each case, and will not be determined by the simple application of a fixed rule of law. The decision to exercise the discretion to intervene in cross-examination, or to refrain from intervention, is one involving considerations of both law and fact and cannot be said to be a question of law alone. Each case will depend on its own circumstances, and no doubt there will frequently be difficulty in deciding from case to case whether the point has arrived in a cross-examination where the trial judge should intervene.

[80]        It has been said elsewhere that the evaluation of whether or not inflammatory remarks are prejudicial and warrant a warning are matters of discretion for the trial judge:  Smagh v. Bumbrah, 2011 BCCA 281 (CanLII), 2011 BCCA 281, para. 8.  These determinations are entitled to deference on appeal.