Partial mocking with OCMockito, OCHamcrest sut calls showAlert (verified in debugger) but the test fails

gistfile1.txt

- (void)testShowsAlertViewWhenOpenInSafariFails
{
    sut = spy(sut);
    // given
    [sut view];
    
    UIApplication *application = mock([UIApplication class]);
    sut.application = application;
    
    // when
    [given([application openURL:sut.url]) willReturnBool:NO];
    [sut openInSafari:nil];
    
    // then
    [verify(sut) showAlert];
}