Seem to think that expanding bolts are used to hold Hughes 500 blades on.
There has been at least one other H300 fatal in the UK due to loss of the tail rotor although it didnt penetrate the cabin, in fact it was never found.
I saw another 300 where the bolt was worn 50% through and the out of balance vibration had elongated all the TRBG flange mounting bolt holes to about twice their normal size.
The gearbox and flange had almost detached from the boom. The only way to remove the tail rotor was to cut the bolt out as it was so badly stepped.
Same system on the older 500's but I 've never seen a similar problem.
The original bolt was a cadmium plated steel bolt later replaced by a special bolt. I do not know if there have been further problems sice the modified bolt was introduced.
Reminds me of a story involving a friend of mine fitting a main rotor to a 205 in a field camp.
One of the oilrig guys was taking a lot of interest in the task. On discovering that only the "jesus" nut retained the whole system he offered to run a few beads of weld around the nut to beef it up a bit!!!!!!!!!! Clearly its not only pilots and engineers who sometimes wince a bit at the aircraft designers offerings.