Can anyone solve me this???

One bright summer day at 2 PM, a shirtless boy named Joe walked into a small, heavily populated store on the corner of Main street and Broadway in a small town in Texas. After turning to the cashier and smiling happily, he proceeded toward the back of the store which was poorly lit. While nobody was watching, Joe, knowing that there was a power outage so no camera would see him, put a chocolate bar in the pocket of his old, worn out skinny-jeans pocket. Joe then picked up a cheap can of Big 8 soda and walked over to the counter. Joe smiled at the cashier once again as he placed 45 cents on the counter, which was the price of the soda. The cashier then pointed to the display on his cash register and said "The price of the soda and the chocolate comes to a total of one dollar and forty-five cents". Joe was stunned for a moment, then agreed to pay for the chocolate. Why didn't Joe try to lie?