Yes exactly. But as Hamilton has been leading on probably most occasions, sometimes with a race winning lead that's instantly been wiped out, in general we can say safety cars this season have not been good news for him.
Also of course at least anyone in a clear second, third or fourth gets the same disadvantage of the car behind them closing up, but they all at the same time get the relative benefit of being closer to the car in front aside from the race leader who has no upside.
I think as you say it's actually wise to not say 'luck'. Let's say they certainly don't always 'benefit' him. (Or whoever has a big lead/gap behind them- although let's face it that's usually him.)