according to the Broncos (it was in the CM), the Broncos asked him if he wanted a release when the Panthers big money offer came in and HE declined it. the club made a decision some time after that, that Wallace was not what the club needed going forward, but they would have met their obligations to him if he couldn't find another club.
On the Raiders, if it comes down to having get-out clauses inserted in some contracts (as the deciding factor on whether a player signs for them), then they may have trouble signing that player, as players (and more so their managers) just wont trust them