When you are dealing with the hobby pilot crowd as a CFI you have to take on a bit different persona than when doing professional pilot, job on the line type instruction. Sky High is correct in not completing a BFR for a now it all pilot. You can't let those type of pilots push you around and a little ego deflation is in order. A "busted" (I know you can't "bust" a BFR) but them not completing one and then having a nice long debrief as to why is often just the humble pie those types need.

I've seen where those type guys will huff and puff and scream and holler only to return hat in hand several days later with swallowed pride ready to learn. The whole "know it all cocky act" is a defense mechanism covering for an insecurity or some type of deficiency in skills or personality. And if they don't return, oh well they are no longer your problem.