Media outlets are going out of their way to misrepresent this case. Kurt Busch isn't saying he believes that his ex was a contract killer, but that his ex claimed she was a contract killer. Look at it from Busch's perspective, regardless if she is telling the truth or not, the restraining order seems more malicious than warranted. If she was telling the truth about being a trained killer she has little to fear from Busch, and if she lied for a period of years about being an assassin, then obviously anything else she says is suspect. Not to mention that her reason for getting a restraining order has changed dramatically depending on the audience.
Were I a judge I would put restraining orders on both of them. Both appear to have very bad judgment concerning the other.