Ember.RSVP.Promise resolved value changes

So, I am trying to wrap a jQuery AJAX request in a Ember RSVP promise, and I have this issue where the value I send to the resolve function (which is the jqXHR parameter) changes from object to string.

The code for doing the request + creating the request is as follows:

return new Ember.RSVP.Promise(function(resolve, reject) {
  Ember.$.ajax([URL], {
    type: 'POST',
    dataType: 'text'
  }).then((data, textStatus, jqXHR) => {
    console.log(jqXHR);
    resolve(jqXHR);
  }, (jqXHR, textStatus, errorThrown) => {
    resolve(jqXHR);
  });
});

And in my controller, I handle the request like this:

promise.then((response) => {
  console.log(response);
  if (response.status === 200) {
    something...
  } else {
    something else...
  }
  receipt.set('busy', false);
});

Now, from the basic (and probably flawed) comprehension I have of RSVP.Promise, the resolve(jqXHR) line should send the jqXHR object as parameter to the callback, right?

Problem is, when I print the response I get in the console, all I get is 200 success, which is the body of the HTTP request I do.

However, when I print the jqXHR before resolving it, it correctly prints the whole object:

Object {readyState: 4, responseText: "200 success", status: 200, statusText: "OK"}

So why is this happening? Is Ember doing some wierd black magic and converts the jqXHR object to string? Or is the data string being sent in lieu of the jqXHR object I am expecting?

Thanks!