Hi,
I believe the proper phrase is, "I call shenanigans on this"
People do things like this for fun so i dont doubt it myself. 4000 amps is just the desired range not that we'll ever see that high.
I considered increasing the AC and DC range of my clamp on too. If multiple wires are used in parallel, i think a good way to see if the clamp is affecting the reading is to measure the current in another wire with another clamp on meter. If the second clamp meter causes a change in reading in the first clamp meter, then we know what to expect and we can figure that into the equation with a fudge factor.