"We would state briefly what in our judgment the law was and is on this question of fault in the offence of driving in a dangerous manner. It is not an absolute offence. In order to justify a conviction there must be, not only a situation which, viewed objectively, was dangerous, but there must also have been some fault on the part of the driver, causing that situation. 'Fault' certainly does not necessarily involve deliberate misconduct or recklessness or intention to drive in a manner inconsistent with proper standards of driving. Nor does fault necessarily involve moral blame. Thus there is fault if an experienced or naturally poor driver, while straining every nerve to do the right things, falls below the standard of a competent and careful driver. Fault involves a failure, a falling below the care or skill of a competent and experienced driver, in relation to the manner of the driving and to the relevant circumstances of the case. A fault in that sense, even though it be slight, even though it be a momentary lapse, even though normally no danger would have arisen from it, is sufficient. The fault need not be the sole cause of the dangerous situation. It is enough if it is, looked at sensibly, a cause. Such a fault will often be sufficiently proved as an inference from the very facts of the situation."