Well, I didn't see any "fact" at all.
And the "expert" finds fault because the medium doesn't duplicate human tissue. I'd say to the expert, "Calibrated gel doesn't duplicate living tissue either", but it does come close to approximating human tissue's consistency.
Regardless, the Bullet Tube material is a neutral medium the same way that calibrated gel is a neutral medium. Your "expert" has nothing to add, really.
You mentioned a conversion equation in your previous post; can you tell us what that is? I'm not a math whiz but I's sure there are others who can figure the ratios.