Rear sway bar upper nut?

I bought the car listed above and the rear sway bar links were just replaced after driving it 1 week a noise started I looked under n the rear right side upper nut was loose I tightened the upper nut when the car was jacked up on that side n it drives fine now no noise but was wondering will that be fine like that how I did it as I read google says to tighten it in load ect, but it was only the upper nut where there's no movement of rubbers etc.