I agree with this, to a point -- triggering "the talk" can be confrontational. As such, is best done in the presence of an established rapport. So, the first time you meet someone isn't always the time to trigger "the talk." That being said, the stutterer in question isn't a novel person. He's known to OP, thus it's up to him/her to judge the strength of their rapport. Presumably it consists only of a series of relatively short business transactions. Thus, the cost of "triggering the talk" (cost to the rapport) might be too high to justify the benefit. But only the OP can decide.