Copyright and License terms are two different categories of law. Copyright is an idea created and enforced by the laws of the country which has jurisdiction. Licenses are a contract between two parties and is covered by contract law.

A thing can be unable to be protected by copyright and also protected by the terms of the license that it is provided under. If a project contains copyrighted code that does not mean that you cannot be held to the terms of the license. Your use of licensed works is granted under the agreement that you follow the terms of the license. You cannot be held liable for copyright violations for using the code, but using the code in a manner that is not allowed by the license makes you liable for violation of the contract that is the license agreement.