Disclaimer: I'm not a 3dprinter guy. I want to be, but I never found the time beyond a partially assembled prusa mendel i3.
....however, I have done an extensive amount of wiring, in various environments, a lot of it on moving parts, and what I can say is that wires of these gauges don't break like this just from movement along that cable chain (or whatever it's called), unless it's incredibly cold environment and/or incredibly cheap wiring.
I'm thinking that you're most likely correct in that it has been pinched.
Whatever shell says can automatically be dismissed as a lie.
Source: I used to work on a survey ship right outside the niger delta roughly 10 years ago. Suddenly on day we were in the middle of an oil spill patch, and the onlyones in the area were us and a bunch of shell drilling rigs. Situations like that happened quite often.