He also killed at least one Vichy French Air Force pilot .. again there's no indication whether that pilot (or pilots) were Nazis.
Perhaps surprisingly large numbers of the military did not support the Nazi ideals.
High ranking members of the military failed to assisinate Hitler several times.
The specific "nitpick" is that the pilot and crew were very likely to not be actual literal Nazis.
That's just history .. the point of current interest now is the question of whether niche ideologies can take over a state and take it to war on the global stage.
Nazi ideals are bad, we can agree.
WWII is especially complex and resistes being reduced to black and white simplistics because of the same kinds of complications that exist today.
Back in the day the UK Royal Family was even more closely tied to their German cousins, many political groups in the UK were sympathetic to Nazi ideals even if opposed to the war expansion .. and the same was true for the USofA.
But, returning to the original point, I see no evidence that Dahl killed literal actual Nazi's.