Given your description of the guy, it was not heartless. He was very unlikely to use it for food or some other necesity.

In a sense the white lie may not be a lie at all but can be interpreted as truth. You said you didn't have any money to give him because in reality you had none to spare.

Remember a couple Fairs ago at Parramatta when that fat lady bum came to me and begged for money because she was thirsty? I offered to buy her a bottle of water and walked with her to the nearest shop to buy it but when I asked the shop lady for a bottle of water, the bum said that she didn't like water and prefered a high energy drink instead. If she were really thirsty she would have been grateful for anything she could drink.

From then on I have ignored her when she begs me for money with thirs or hunger as the excuse because I know that she doesn't really need it and is all a scam.