Yeah, totally. There's different types of "bulks". I'm not suggesting he eat at a huge calorie surpless, just that he makes sure he's not on a deficit, eat enough fat and protein, and to hit the gym so that his muscles develop.
So basically, over time, if his weight slightly increase it will mostly be lean muscle mass. If it stays the same, he'll still have burned away some of his fat stores and increased his muscles.
I think the reason why people say it's impossible is because many people look at exercise as some sort of race. Like, "I wanna be shredded by Spring" or "I wanna bench 300lbs in a year" or something. In which case, ya, it's not really possible.
But, if instead of looking at it as a race you look at it as a marathon or a lifestyle, then it is totally possible. I've been eating like this for the past 6-ish months and I have slowly, but surely, lost fat, increased muscle, gotten stronger and have become much nicer aesthetically. I only went from 175 to 165. I have no where near the results of some of the people who have those insane "one year transformations", but I am planning on being healthy and fit my whole life, so I am doing something that works in the long term.