Speaking about the league, I think this one would get vetoed by them if it wasn't Lakers...
The league has no right to veto a legal trade.
With CP3 , the New Orleans were in weird spot. Owner wanted out or died not so sure, so the league collectively decided to buy it, and then sell it within a season or so. So, during that time, the acting owner was the commissioner.
So when the deal agreed, he stepped in, and did his job as an owner.
Very rare and exclusive case, that was exacerbated due to bad front office, and the name of the lakers.