Just a couple of points...
1) UofL was looking into building an on-campus facility before the city got involved with an eye toward placing it Downtown. UofL didn't force anyone to come up with such a sweet deal and would've been okay playing in Freedom Hall until an on-campus arena could be constructed. It's the city that wanted an arena downtown so badly and they got the state to back them up. The only reason UofL had any leverage was because they didn't want to go Downtown.
2) UofL pays higher annual rents for the arena than all but maybe two NBA teams. There's one faction in town that thinks getting an NBA team would bring the arena more revenue, but NBA teams siphon funds from arenas they don't generate funds. So, I don't think this is a realistic solution.
3) The bonding authority comes from the Louisville Arena Authority, not the City of Louisville or the State. So, the city's bond ratings aren't in jeopardy.
4) Initially the State Fair Board ran the day to day operations and pretty much had things running as a crony reward system. This was thanks to the State's political involvement which was thanks to the City's getting involved. The Arena Authority eventually cancelled the Fair Board contract, replacing the management with AEG. AEG guarantees an annual surplus from operations of at least 1 million dollars, but has been running closer to 2 million, IIRC.
5) Removing the Fair Board caused another batch of conflicts because the Arena Authority was supposed to guarantee them any lost revenue from events leaving Freedom Hall for the new arena. Naturally, the Arena Authority could be considered in breach of this because they haven't been paying anything. But as the disagreement is between two state entities, there's no risk of lawsuits. The polities are fun to watch, especially the UK backers going apoplectic.
6) The financial agreement calls for the City to subsidize the arena up to around $10 million per year. There are differing reports, but this might not be enough extra to service the bond debt. It could be an ugly situation. The primary cause is that the TIF district has woefully under performed expectations. If there's a case for any fraud investigations, focus on that.
7) All this ugliness is the City's own fault for pushing to get the State involved, unleashing all the usual cronyism from that quarter. This included Jim Host the original chairman of the Arena Authority, a huge UK booster. It's cronyism all the way down when the State of Kentucky gets involved.
8) If the bonds default then UofL is supposed to have the right of first refusal to buy the Arena. I'm not sure how that would work, but assumably, they'd have to at least match any other bids. I'm sure the NBA advocates would be all over the opportunity.
9) My personal perspective is that the City and the State hoodwinked any bond investors by isolating all the liability of default within the Louisville Arena Authority as a separate legal entity. It's possible that some liability could leak to the State or the City but it's difficult to see how.
10) Let's not forget that UofL was not the driver of any of this, and worst case, will just return to Freedom Hall.