I don't know if this is an issue with React or IE11 but when an the input initially contains an EN-dash (8211) it fires the change event. 
JSFiddle http://jsfiddle.net/uH539/10/

expect(console.error.argsForCall.length).toBe(1);
    ReactTestUtils.renderIntoDocument(<input type="checkbox" checked="false" />);
    expect(console.error.argsForCall.length).toBe(2);
  });
  it('should warn with checked and no onChange handler with readOnly specified', function() {
    ReactTestUtils.renderIntoDocument(
      <input type="checkbox" checked="false" readOnly={true} />
    );
    expect(console.error.argsForCall.length).toBe(0);
    ReactTestUtils.renderIntoDocument(
      <input type="checkbox" checked="false" readOnly={false} />
    );
    expect(console.error.argsForCall.length).toBe(1);
  });
  it('should throw if both checked and checkedLink are provided', function() {
    var node = document.createElement('div');
    var link = new ReactLink(true, jest.genMockFn());
    var instance = <input type="checkbox" checkedLink={link} />;
    expect(() => ReactDOM.render(instance, node)).not.toThrow();
    instance =
      <input
        type="checkbox"
        checkedLink={link}
        checked="false"
        onChange={emptyFunction}
      />;
    expect(() => ReactDOM.render(instance, node)).toThrow();
    instance =
      <input type="checkbox" checkedLink={link} onChange={emptyFunction} />;
    expect(() => ReactDOM.render(instance, node)).toThrow();