Not true at all.
If you read back, my comment of making clean through and through shots with large calibers and "meat loss" was in response to the previous post (which I quoted) discussing just that.... not head shots.
Although, I would argue that even with head shots with large calibers that the hydrostatic shock and bone fragmentation would be considerably greater than with a .22 or similiar. Lighter loads or not... "X" FPE is still "X" FPE. That's just physics.