Maybe Kill overheard Fleck call it "BUTTgers" when talking to the student-athlete?
Or told the player about what a sh!t-hole New Brunswick, NJ is (don't know personally, though based on the parts of NJ I've seen I'd have a tough time believing it's not).
I'm guessing Fleck's reference to culture was "recommended" by Coyle. When I heard it, I took it more as saying getting the players to believe they can be in the National Championship conversation, not cleaning up the program. Which to me didn't come across as a shot at the previous regime(s).
Coyle's comments definitely came off like a shot at the previous regime(s). That probably prejudiced Kill that when Fleck said "culture" it meant something different.
But the rumor has been out there that Fleck didn't jive with Kill/Kill's staff at NIU, perhaps there's been bad blood for a while and this just was the latest example. Add to that everything else (Fleck replacing Kill's chosen disciple, Coyle questioning the integrity of the program, etc.) and it probably won't be sunshine and roses between the two of them anytime soon...