The wreckage I've reviewed has normally an intrusion of a blade into the cockpit, but not strikes on the boom. boom strikes and cutting of the boom have been seen with a gross cg shift from structural failure of the TR/TRGB.
fdr, all I can say is that my experience has been quite the reverse. The accident detailed above there was only the tail boom chop and was not the result of gross CoG shift such as from from structural failure of the TR/TRGB . The aircraft landed flat on its skids with the cabin top being not much more than chest high, as though someone had stomped on the aircraft with an enormous boot. The original grey coloured interior now being blood red prompted me not to take photos, as did picking swatches of nomex flight suit with attached flesh off bolt heads in the two man compartment.
Of course you're correct in that it may come through the cabin, to quote an extract from one report, "As the fuselage continued into the right roll the main rotor blades sliced through the cabin 3 times; first severing the roof of the canopy, then the control panel, and then the cabin floor through the center. The accident wreckage revealed that the cyclic pushover must have been so abrupt that once the low-G situation was reached it would have been impossible to recover from".
Be interesting if anyone has written anything on rotor dynamics post separation, perhaps the combinations and permutations are so complex as to prevent any understanding.