I Single vs. Double slit coherence clarification please?

[PhysicsIsReallyFun]

TL;DR

Single slit electron detection - Is wave nature still observed?

The woman in the video below is claiming everyone has the double slit experiment wrong. She is claiming that when electrons are detected as they pass through the slits decoherence does not occur, what is happening is that the electron wave only passes through one of the slits.

Her "proof" is that if you detect the electrons in the double slit experiment the result is not two bands of particles on the screen behind the slits but rather two diffraction produced interference patterns.

We can simplify this experiment to a single slit. If electrons are directed through a single slit a slight interference pattern is produced due to the electron wave diffracting through the opening. I had thought that if a detector was used the electron wave would disappear and the result would be electron particles and no interference pattern observed due to diffraction?

She seems to know what she is talking about and now has me confused?

 

[PhysicsIsReallyFun]

Specifically at 9:00 in the video.
She says that when you have a detector before both of the slits, this "forces the electron to collapse to just one of these (waves) and you see a single slit interference pattern."

Is this the biggest lie in physics as her video title claims or is she greatly mistaken, to put it nicely?