LA boo boo???  

People are reporting that this aircraft was a Soloy conversion AS350SD2, which removes the original Turbomeca engine and replaces it with a Lycoming LTS101.  I never flew this engine in this aircraft installation, but I did in the Bell 222 and BK117.  The LTS101 had an emergency failsafe where if the N2 rpm reached a certain threshold, which i don't remember (113%?, 116%?), a gear wheel would shift slightly and sheer an airline to the fuel control, which effectively reduces power to idle.  The LTS101 in the old days was notorious for catastrophically failing and throwing turbine components through the other engine, creating a dual-engine failure.  If this feature still exists for engines in single-engine installations, I don't really see the benefit.  In fact, it creates a confusing situation where the aircraft indicates a high-side failure, for which the emergency procedure would include increasing collective pitch to control Nr/N2 rpm, then fails the engine while you're at a high pitch condition.  It would be far better to allow the engine to overspeed momentarily, have the pilot control it with throttle leaving time and power to effect a powered emergency landing.