The V2500's suffer from rotor bow. The cause of which has been determined to be uneven cooling within the engine. Hence it is vital to ensure that the engine has thermally equalised before shutdown. My guess is that your company ops were different and it has now become a costly short cut.
That said, in my opinion the main reason for the rotor bow problem is crew spooling up the engines to get the a/c that last few yards up the ramp and then just shutting down instead of allowing 5 mins cool down. Heard it many times and always gave the pilot a b*****king when I saw him.
