Having spent several years as an ab-initio instructor, I've had experience of some of the more adrenalin raising moments in life, especially on low-inertia rotor types.
The first of these was during a practise engine failure during the climbout. As I started to partially roll the throttle back on the student the engine cut-out completely and we had an exciting moment or two during the 400 feet left between ourselves and the ground. All went well on this occasion but the schools procedure regarding carb heat setting for climbout was adjusted as a consequence.
The second was far more exciting when, during a practise EOL (with the throttle wound back to idle) the student was thrown by some windsheer at low level. As I reached for the cyclic and was about to say those immortal words "I have control" the student flared with such force on the cyclic that he nearly broke my thumb. Unfortunately, he also managed to push the tail rotor straight through the ground culminating in not much of the machine being left in one piece. Neither one of us was hurt, at least not physically.......
Having said all that, I continued for several more years teaching students and ensuring that they conducted many EOLs.
As far as I am concerned, the ability to carry out EOLs succesfully is paramount for any would be helicopter pilot as nothing can better prepare a pilot for the real thing than doing if for real, or at least as real as possible.
As for the training accident...... I would far rather fly with a pilot who has been through some sort of real emergency in his/her formative training than to fly with one who has never had such an experience. Not that I am suggesting that everybody should go out there and smash up a machine during their training!! I just think that going through something for real tends to impart a whole new respect for the dangers of flying.