As one of the people involved at Transport Canada when this happened, perhaps I can shed some light on this.
Unless there has been something else happen to the tail rotor since 'the fixes' were put in, there were only three incidents of tail rotor being chopped off. In all three cases, the pilot was able to land the helicopter, and the only fatalities were in the last one in South America, where the passengers exited the aircraft with the rotor still turning and were hit by the main rotor blades.
Perhaps there has been something else happen since then.
There was one other incident that was thought to be a possible tail rotor strike, in the Gulf of Mexico, but it was later determined that the pilot had had a fatal heart attack- the damage to the tail boom was not consistent with a tail rotor strike on the boom.
The fix was an 'active' tail rotor stop that came in when the airspeed went above 50 KIAS and retracted at about the same speed.
This latest incident sounds like something similar, and it's going to be interesting to see what happens.
As for similarities to the OH-58D - yes, it has the same tail rotor, but the OH-58D can't go anywhere near as fast as the 407, and that appeared to be part of the problem- hence the airspeed restrictions that were put in place until the fix was sorted out.
Hope this helps to clarify things.