Is it normal for a taxi driver to tell you to take a cheaper one?

I got into a taxi on Al Reem Island one evening and asked the price to the Corniche. The driver looked at the meter, looked at me, and said, it will be cheaper if you walk to the next road and flag another one. I did. He was right, it was a third of the price. I rarely meet a man who talks himself out of a fare. I hope someone tips him extra. I hope it is a person who also flags the next road. I wrote his plate number on my hand. It has washed off.