Apparently because she want's Putin to poison her entire family with polonium-210.
That's the critical point. She had to be aware of the consequences of disobedience. Therefore, it is highly unlikely to be disobedience. Putin has almost certainly given the OK for her to talk even if it exposes more of the operation. (Obviously, one agent wouldn't have known the whole operation anyway...) But if he is abandoning the entire effort to influence US politics, he's going to be abandoning Trump as well. Any expendable assets will already be removed/destroyed, and any backstops on the Russian side that Trump was counting on will have been removed even before she was allowed to talk. He's going to be facing the domestic reaction with no help.