Was there a difference in the number of electrons striking the target and the number of electrons emitted? That is a fairly easy thing to measure.
I would like to know if there was a difference with and without the 2nd slit being closed.
Passing a stream of electrons through a pair of closely spaced slits and seeing an interference pattern similar to light would not be surprising as within that stream each electron would have some small effect on any other electrons near it, possibly pushing them to the side enough to go through the 2nd slit. All of this I have had to deal with in color CRT (picture tubes) construction.
To believe what they are saying would require understanding how 100 electrons could be emitted, some or all passing through 2 slits at the same time. Seems we would for a moment have more than 100 electrons and where did they come from?
As far as the duality, never liked that word and they may have seen too many episodes of Star Trek TNG. Duality was Counselor Troy's favorite word. New age mumbo jumbo.
But what if the interference pattern appears when you use one electron or photon at a time?
which is how the experiment is done.