So you are interviewing a candidate on December 4th for this key position - you identify someone who you feel is a very good fit - you are ready to make an offer - you ask "how soon can you start?"
They say "Well, Because of the special project I'm on (and the rules of my bonus plan) I have to stick around to help manage a part of this huge nationally televised presentation that you have heard we are doing in Arizona on January 1st .... after that I'm ready to be exclusively focused on the new job,"
they may go on to say "along the way, I should have some real quality time to get started on some of the fundamentals of this new position with your organization"
Do you stand up and say "absolutely not! if you can't quit and walk out of your position immediately, we don't want you " of course not! - would you hire somebody who would quit & depart a job with zero notice? no!
We do not know the terms that Ash discussed with Hobbs we do not know Hobbs' contractual obligations ... basically there are no details to be had - - will learn more tomorrow.