What is the burden of proving the absence of an immediate hazard at the moment the driver begins a left turn?

Section 174 of the Motor Vehicle Act casts the burden of proving the absence of an immediate hazard at the moment the left turn begins on the left turning driver: Nerval v. Khehra, 2012 BCCA 436 at paras. 28-29. Justice Harris explained that a “left turn must not be commenced unless it is clearly safe to do so. If there are no vehicles in the intersection or sufficiently close to be an imminent hazard, the driver may turn left and approaching traffic must yield the right of way”: at para. 33.