ng-leave class not getting applied

I am using animate.css and Angular.JS for my project. I have created a codepen which you can find here: http://codepen.io/SassyCrafter/pen/NrRbmE. The following CSS (PS i am using SASS)

.form-message {
  position: absolute;
  .message {
    position: absolute;
    color: white;
    background: orange;
    padding: 5px;
    position: absolute;
    white-space: nowrap;
    border-radius: .20rem;
    z-index: 1001;
  }

  &.ng-leave {
    animation: fadeOut 300ms;    
  }
}

If you have a look at the pen you can see that when the email is not valid, it fades in like it should. But when the email is valid and it is supposed to fade out it simply stays idle for a bit then abruptly disappears. Any help would be appreciated.