"The way many of these NHL contracts work is simple. If another team wants to hire an existing staffer who is already under contract and is granted permission, the new team can hire said staffer. The team with an existing contract would pay out only the difference in salary if that staffer took on a job that paid less.
In Keefe's case, his contract not only had more term (four years), which was important in this kind of deal, but, as Lebrun puts it, pays more on an annual basis, leaving Toronto completely off the hook in paying Keefe."