Fusei Kise studied under Hohan Soken.
The misplaced justification for people to say such things is since Hohan Soken bypassed the 'Japanification' of his Shorin style since he moved to S. America in the 30's and returned in the 50's (just going by memory, I don't remember the exact years).
That doesn't say anything more about lineage than say Higashionna's lineage. Unless they are a bushi-class snob I suppose. What it DOES say, is that Hohan Soken's version of Karate probably had the least amount of watering-down since it wasn't really influenced by the mass-production mentality of the 30's and 40's. There were hints of evidence that suggest there was some amount of holding back on some of the teachings-in effect watering it down for public consumption, but I certainly don't know for sure.
However, SINCE the 1950's he has had good and not so good students...some were not even students but claim to have been. From what I understand and heard, Fusei Kise is one of the legit good guys....but even some of HIS students are good/bad/ugly. and so on. It happens in every Art.
To be bragging (like your guy did) that his art is decended thru a well known Master doesn't say anything about the sensei who claim to have studied thru that Master.
Find out the sensei of this guy...BuDoc might know them.
The lineage argument of this particular style is a well known argument and a source of pride....sometimes it is misplaced. The only time when it is not misplaced is when the person holding that lineage doesn't brag about it.
all this is just from what I've read and heard from various sources...it's not first-hand (except the opinions about bragging