Moral dilemma - What would you do?

As some of you may know, and most of you likely don't care, I am the business development manager for a small investigative firm. My primary job responsibilities basically involve onboarding new clients and overseeing the sales and marketing process. My job doesn't require a whole lot of selling (read: No cold calls. Wheeee!) but I manage the entire selling process and the 5 people that make things happen.

The sales process is very difficult in this type of business so I tend to be very selective in retaining employees. However the good ones stick around for a year or so, then leave on good terms to pursue other career options. In those cases, they've invested a ton of time into generating new business, so I keep them on payroll and continue to pay their commission even after they have left.

There is a point here - I promise. Recently one of my long-term employees abandoned her post after a disagreement over excessive time off. I re-assigned some of her work load to another employee, who managed to cash in on some of it. My policy is this: if you're not eligible for rehire, you're not eligible for commission on new business you generated. So now that's coming into question. I am a nice guy but I am not a very compassionate guy.

My attitude is this: I'll be good to you if you're good to me. If you dick over your team, why should you benefit from it? No soup for you!

 But the Devil's Advocate would say that the former employee should still be paid for his or her work (for the record, it's NOT a commission-only gig, but the commission is still decent), regardless of the terms of dismissal.

Where do you stand? Unbiased opinions please - if you feel I'm a heartless dickbag, don't be afraid to say so. Even if you agree with me.