Because this hits right into my area of expertise (25 years) I thought I might give you a bit more insight into what is shown here. I now work for JEOL and in the past also worked for and with Tescan (the SEM brand in this video)

At first, he loads two samples on carbon tabs, and the material seems to be ceramic.
Then he images these samples at 20kV, using the Secondary Electron Detector.
Ceramics are mostly insulators and don't conduct electricity well. In a SEM this will cause problems, and the higher the voltage used the heavier the effect: The electrons that are used for imaging can't escape in a normal way, causing local charging and discharging effects. These effects usually result in many different kind of imaging artifacts. One of them is this rectangular patterns 3:19 into the video. "it doesn't look like mother nature" someone says. But of course this looks weird if you don't know what really happens when you are looking with improper conditions or not well prepared samples.

At around 3:40 the holes seem to get bigger, but this is just the charging effect, also at 3:46 this is exactly what happens in the top right of the image. You can see something light up and get darker. The longer the same area is bombarded the samples gets charged up, creating a local electric field which charges and discharges. Someone asks isn't this just the beam doing this? Well, it's just exactly that! In combination with an insulating sample.

Then they "switch it off" , but at 4:09 it is still in external scan mode. The external scan is used for the EDAX system that's attached to this microscope. This system identifies the chemical composition of what you're looking at.
Now... if you are looking at "alien material", the first you would like to know is what it is made of, wouldn't you?
Well, this is what the EDAX system is for. The only reason not to show this is because they would probably reveal that the material is something like alumina or some other very common ceramic material. Because the system is coming out of external scan mode I guess they just finished with the EDAX measurement and concluded it's nothing special.

Then they compare two images. One taken at 10kV and one at 5kV. Indeed they are different. But the magnification is really low for a SEM, and the penetration depth difference of 5kV vs 10kV is not the reason for the differences in the images. It's all charging effects. I guess they did a relatively long EDAX analysis, at 10kV (you generally use a higher voltage to excite more electrons and get a better spectrum) , while heavily bombarding the sample, after which the charging effect of the sample is in full effect.

Any experienced microscopist would not bother looking at this sample this way when the charging effect is so heavy. Standard practice would be to go to Lowvac mode (20-100Pa pressure) to eliminate charging, or simply coat the sample with a conductive layer to avoid charging effects. Using 1kV is another trick that can be used to reduce charging effects, but the Tescan Vega system is not so good at imaging under these conditions, and you can't use the EDAX at 1kV. Also, on these systems 1kV is not for novice users, because this requires heavy manual adjustment of this microscope.

Also, Dr. Patchett seems to be an expert in a different field of Physics and I don't see any track record on electron microscopy. What I see in this video is a novice user improperly analyzing a non conductive sample, making many beginner's mistakes.