I will probably be corrected, but I am not aware of anyone being held to this commitment and actually paying a company for their training. All this does (IMHO) is make you feel as if you owe the company. The FAA requires the employeer to provide you with training in order to operate their aircraft safely and competantly.
If anyone has a link to a case where a pilot was forced to pay a former employeer for the employeer provided training, please post.