What is the test for a motorcyclist to be found guilty of driving under the influence of alcohol?

Vehicle Code section 23153(a) is clear on its face that "[i]t is unlawful for any person, while under the influence of an alcoholic beverage ... to drive a vehicle and, when so driving, do any act forbidden by law or neglect any duty imposed by law in the driving of the vehicle, which act or neglect proximately causes bodily injury to any person other than the driver." (Italics added.) In People v. Oyaas (1985) 173 Cal.App.3d 663, [202 Cal.App.3d 206] 667, 219 Cal.Rptr. 243 the appellate court identified three distinct elements which must be proved to establish a violation of section 23153.