This is exactly what I thought. I think this deal gets done because the incentives for all three parties are in line by overpaying Hill.
The Jazz can benefit from paying Hill more than he would get on the market because they have about $4M that they will have to pay in order to reach the salary floor. This means that they can overpay Hill by that amount and it is "free". Next, assuming Hill's market value is below 3 years at $88M, by including $13M of the market value in this year's salary they can structure a deal which underpays in subsequent years. This will create a future asset and provides flexibility (because they can trade it away if needed). Additionally, a deal would provide value as a signal to Gordon.
Second, Hill's new agent is incentivized to get this deal done because if he turns down an offer that is better than what Hill can get later on the open market his reputation will be damaged.
Finally, Hill will be happy with an over payment because he makes more money!
So you see, all parties gain from an over payment, and equally important, everyone is a looser from not getting the deal done.