The binman in this case clearly struggled to operate Olive Stevens' vehicle after offering to help her drive around some rubbish blocking her path. He held only a provisional license at the time of the incident, a license that happened to be expired. The binman likely backed over Olive Stevens while carelessly attempting to operate her automobile.
The binman is at fault for killing Olive Stevens. He was driving at the time she was hit and killed. Since he was behind the steering wheel, he is at fault. Thus, he should be required to comply to the punishments for his crime as described by the law in Kent.
While the facts in this case seem to be confusing, what I have read seems to leave a lot of unanswered questions. Why didn't the binman just go pick up the trash and get it out of the street? Why would an elderly woman let someone else drive her car? Did the binman even drive her car? Who lost control of the car? Was Ms. Stevens hit by the car? What caused her injury? So far I see no conclusive evidence what may have caused the accident and her death.
It's not clear exactly what happened. It seems the "binman" was offering to help Ms. Stevens, since her access was blocked by the rubbish truck. He may or may not have done something careless,but it sounds like he was trying to be helpful, so without more facts, I can't say whether or not he was at fault.