I have some respect for Steve Kerr here. Everyone knows you're hungover, even if it's ring number 9 for you. You could try to play it cool and downplay the night or you do this. Get ahead of the story and admit you basically housed all the Taco Bell and Excedrin to try and get rid of the hangover. Really this is the only good type of hangover though. The celebratory hangover. It can be winning the NBA Finals, your wedding, your team winning, etc. If it's something you did and celebrate that's the only positive hangover.
That said he combined it with probably with the worst hangover experience - flying. There's nothing worse than having to sit in a plane for multiple hours just knowing you feel like dick. I say this even as a dad. Watching a kid with a hangover? You just sort of roll with it, put on some TV and hope you can lay down for a little. You can't escape a plane - even a team plane. You're stuck in that metal tube up in the sky praying there's no turbulence whatsoever.
Kerr's gotta be smarter here though. It's ring 9 man. You gotta know to keep it rolling. Don't let the hangover hit until after the parade.