Selling for less than purchase to avoid capital gains

[James Wilcox]

I recently talked to a motivated seller that is interested in selling a small multi-family property. He states that he is looking to avoid capital gains tax and wants to do a 1031 exchange. He purchased the property for 100k and now wants to sell for 75k. My question is if he is selling for less than his purchase does he even need to worry about capital gains? I think there would need to be "gain" there to be a tax.