He was maybe confused since it's now forbidden to smoke in many large public areas outside of confined spaces marked off for smoking, like the areas around train stations. There's less smoking-and-walking in general.
From my understanding and observations when I visited Japan for a couple of weeks, Japanese people don't eat/drink/smoke while walking. Even for outside vendors, they will eat it on a nearby bench or stand and eat it before moving again.
I did see smokers often in the smoking areas. More than I see in NYC.
An exception to this that I wasn't aware of until just last month is the boarding platform for the bullet trains in some stations. I had to walk through a dense cloud of cigarette smoke on my way to my bullet train car at 9am on a Sunday. That was not pleasant.
I did see smokers often in the smoking areas. More than I see in NYC.