I'm an idiot. You just use the same axis event and wait for 'no direction'. For those searching for this here is how it's done.
So I press a button and this canvas activates. When it does, the playmaker FSM runs. So I start out by waiting for a 'no direction' as from the button it is still pressed. Then after pressing a joystick button again, I also wait for a 'no direction'. This basically is waiting for the joystick button to be released.