I don't put a lot of stock in the second test. Assuming the same people were involved, it's likely they were (consciously or not) being a lot more gentle with the devices.
I was one of the medics there. The failures have stopped after the modification, even with new medics. One of the major issues is that it's such a chaotic scene that it is essentially impossible to fine-tune the stress applied to the device, so your specific concern doesn't apply here. Our testing on the bench also showed that the refined windlass (rod thing) did not cause the same failure even when about 10x the force was applied.
We have received ethics approval for a proper (unblinded) head-to-head multi-site RCT between our 3D printed version, our desktop-injected version and the premium brand, but it will take time for that data to shake out.
There's also the photo of the dead paramedic, which while it isn't explicitly graphic, it would certainly be reasonable for someone to find it upsetting.
https://medium.com/@trklou/3d-printed-tourniquet-day-2-of-ga...