Why is this bearing calculation so inacurate?

Is it even that inaccurate? I re-implented the whole thing with Apfloat arbitrary precision and it made no difference which I should have known to start with!!

public static double bearing(LatLng latLng1, LatLng latLng2) {
 double deltaLong = toRadians(latLng2.longitude - latLng1.longitude);

 double lat1 = toRadians(latLng1.latitude);
 double lat2 = toRadians(latLng2.latitude);

 double y = sin(deltaLong) * cos(lat2);
 double x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(deltaLong);
 double result = toDegrees(atan2(y, x));
 return (result + 360.0) % 360.0;
}

@Test
 public void testBearing() {

  LatLng first = new LatLng(36.0, 174.0);
  LatLng second = new LatLng(36.0, 175.0);
  assertEquals(270.0, LatLng.bearing(second, first), 0.005);
  assertEquals(90.0, LatLng.bearing(first, second), 0.005);
 }

The first assertion in the test gives this:

java.lang.AssertionError: expected:<270.0> but was:<270.29389750911355>

0.29 seems to quite a long way off? Is this the formula i chose to implement?