That's hair-splitting nonsense. Drone victims are very often neither combatants nor suspected combatants but rather local warlords/politicians. In many cases the US forces do not try at all to determine whether the victims are combatants (i.e., whether they are holding a gun in their hands, for instance).

As the article lays out the assassinations are made based on death lists compiled by US intelligence agencies. They can put whoever they like on these lists, in this case they put a US citizen on it, for example. That's the paradigmatic example of political assassinations, and e.g. on a par with what the US did when they supported death squads in Chile, except that in Chile the death squads were mostly comprised of non-US citizens whereas drone strikes are conducted by US citizens.