They expect to get ahead by taking shortcuts. And they can't bloody well handle it when others succeed.
In order to share the planet with difficult people, it often helps to try and guide them to more productive behaviour (easier said than done). In this case it would be helpful to let such a person think from a more abundant mindset, rather than through fear of loss (being a far more powerful and ultimately stifling emotion). Seeing the success of others can trigger fear of loss and lead to negative behaviour. Removing your mind from competition into creation will bring you above this fear-reaction cycle and lead to a far more balanced lifestyle, in my opinion.
Easier said than done indeed. I really like how you took the serious approach. There is a problem. That's true. And most problems can be solved. But...
One must first get to the point where they see it as a problem, but when convinced this behavior is all that's needed to get ahead, it could take a lot of work to break that cycle.
We should get Dr. Phil on the phone. He'll know what to do.