Tap on the Shoulder

A true story (allegedly) from the pages of the Manchester Evening Times:
Last Wednesday, a passenger in a taxi heading for Salford Railway Station, leaned over to ask the driver a question and gently tapped him on the shoulder to get his attention.
The driver screamed, lost control of the cab, nearly hit a bus, drove up over the curb and stopped just inches from a large plate glass window.
For a few moments everything was silent in the cab. Then, the shaking driver said "Are you OK, Sir? I'm so sorry, but you scared the living daylights out of me."
The badly shaken passenger apologised to the driver and said, "I didn't realise that a mere tap on the shoulder could startle someone so badly."
The driver replied, "No, no, I'm the one who is sorry. It's entirely my fault. Today is my very first day driving a cab. I've been driving a hearse for 25 years."