I really like Zack's work - his lighting and tones are impeccable - especially his night photos that really capture the people. And, he seems to really like people, which many photographers are ambivalent about.
However, I am not impressed with his advice to street photographers on how to sneak photos of people - it just strikes me as abusing a relationship - especially those of us from the global north with money who photograph people in the global south. At least have the courtesy to engage your subjects.
To that end, his advice to bring along an instant camera to give back photos to the people you photograph is excellent. In El Salvador many years ago, I spent more money on Polaroid film than on the slide film for myself, and it was very gratifying to give a little photo back to people I was photographing.
Why are most of the comments supportive of Nikon aiding killing trophy animals, not addressing this point: "research by Scientific American magazine research that suggests the practice may have contributed to a halving of the population of lions in Africa over 30 years." It is not about free choice or the market - as animals don't have that option, do they?