The part where you think that it passes light to the observer.
Which just demonstrates that you fundamentally fail to understand how cameras work.
Let me ask you this, if you used a mirror to look at the sun, do you think your eyes would be fine?
You can group cameras into basically 3 sets.
Set 1 - The viewfinder is separate to the main camera component. e.g. this one:
The light goes straight into that viewfinder, through a few lenses, and into your eye.
If you look at the sun through this, you can very easily go blind.
Set 2 - SLR - This uses a mirror to direct the light from the lens through a prism to the viewfinder. When you take a picture, that mirror moves out of the way. Again, this setup has the light go bounce off a few optical devices and go into your eye. If you look at the sun through this, you can go blind.
Set 3 - Digital "viewfinders" - This uses a camera to take a video feed, and then display that video feed on a screen. In this case, there is no path for the light from the sun to reach your eyes. The light reaching your eyes is produced by the camera, not the sun. So as long as you don't go out of the shadow of the camera, you are fine.
So again, what part was balderdash?
Do you think the camera will magically protect you if you are using set 1 or set 2?
Do you think you can use a mirror or a magnifying glass (or both) to look at the sun and you will be fine?
This is why you can look at the video without going blind.
Notice how I never said anything about the video? I talked about the camera. Depending on what type of camera you have,