I think it’s a common sense that in Neither … nor structure, verb conjugation depends on the subject (singular or plural) closest to the conjugated verb.
But please refer to the following article,
nytimes.com/2012/05/07/world … s-arc.html
and go to the last sentence of paragraph 6, which reads
“Neither Mr. Bo nor Ms. Gu have been given an opportunity to defend themselves publicly.”
So there is a mistake here right?