Again, minimal tools for the difficult to understand. No special x-rays machines to determine cracks in insulation or how far to incise, lamination machines, vacuum pumps, ovens, dc high voltage sources to make sure no bleed, and no pressure devices to compress the curing polymers.
What is depicted there is a standard working procedure to fix the defect (most likely insulation defect, but this looks just like a "dry" marketing demonstration of the repair kit), done the same way all around the globe on this type of cables.
And for that part of the job (that is in fact very small fraction of the total work on that fault) you indeed do not need any tools you mentioned.
What it does not show, how they come to knew where exactly the defect was, so where to perform the fix.
And it does not show the work quality check after the fix is done.
If you need any "special tools" like Xray, HV tests or so, it is for these two parts of the job that were not shown in the video at all. So there is no way to claim they did not need them... And by the way these two occupy way longer time (mainly locating the fault), but nothing of that was part of the demonstration.