Sorry, Patjew:
From what I have read this is not always correct. He can be signed to a new contract by his old team and then traded, which allows the new team to pick him up at whatever the "new contract" is worth. This does take some fenageling but is possible.
Which sort of goes along with BB saying on WEEI that he wouldn't do anything until Peppers had signed his franchise with Carolina.
It is always dangerous to take one situation and apply it to all possibilities, it quite often spreads incorrect information.