And from ESPN's Marc Stein:

It could turn out that this was, in fact, an insurance issue, though the specific dramatics involved remain under wraps. (They may remain so if it is an insurance deal; I'm not sure how the law or insurance companies feel about all of this business.) While "slightly" is a relative term, the Kings (without Hayes) are at $44 million in committed salary, $2 million under the payroll floor. Hayes' first-year salary would have been $5 million under the old deal; with the cap at $58 million, there's no real current year cap space worry about raising Hayes' contract.

Let's hope we can officially welcome Purple Hayes back this weekend.