The RoFR certainly exists. Aaron Bruski was able to get a copy of the legal documentation and confirmed this in a story. [
link]
Whether Kehriotis would succeed in blocking a sale in court is I suppose a question for the judge who would get the case.
There's been some discussion about whether or not the NBA has the right to reject an ownership transfer to minority partners. It's possible (I'd lean towards likely) that the BOG
could (not necessarily
would) reject a purchase bid by Kehriotis.
That's what Crandall reported last night - that Kehriotis has $350M ready to buy the Maloof/Hernreich shares and another $400M promised to build an arena. I will note that Crandall has a relatively poor track record when reporting on magical arena investors coming out of the woodwork and that the timing of the announcement (one day before the first "binding" city council vote) is a bit suspicious.
I suppose that the story is a best-case scenario. An investor who is legally in line in front of Hansen buys the team and builds a brand new arena downtown without using any public money. But I'm not much of one for fairy tales, and until the fairy actually emerges it would be silly for the city to stop moving forward.