the fact it’s a Boeing is irrelevant. This can just happen.

That seems like an open question, given quotes like this:

Jokat said there was no turbulence after the incident and once the plane landed the pilot came to the back of the plane in “shock”.

“I asked ‘what happened?’ and he said ‘my gauges just blanked out, I lost all of my ability to fly the plane’.”

Source

It's just one passenger's word so far, but it merits investigation. Sounds like it could have been a problem with the plane.