Surprise Price Adjustment at Lowes

I had a pleasant surprise at Lowes on Christmas Eve. The story started last Wednesday Dec 23, when I stopped at Lowes to get 3 strands of lights and 1 lit garland. I chose Lowe's because all Christmas was 50% off. I took my goodies home and plugged in the first strand, which immediately shorted out. I was too tired to worry about it then, but the next day George was heading into town so I asked him to take the defective strand back and get me the same thing. He came home later with an odd look on his face, then handed me a bag with two boxes of lights and said, "I got $8 cash back". Huh?? It turns out the receipt was in the bag, and when he presented it with the bad strand, the cashier looked at it and said, "Christmas is 75% off now, so I'm going to refund you the difference on everything." She handed him some cash, and with it he was able to get 2 boxes for what I had paid for one, and he came home with $8 in overage. I don't know if it is Lowes policy to price adjust after the fact, or if we just lucked out, but it was a happy moment.