The existing physical boundaries of a unit or the physical boundaries of a unit reconstructed in substantial accordance with the description contained in the original declaration are its legal boundaries, rather than the boundaries derived from the description contained in the original declaration, regardless of vertical or lateral movement of the building or minor variance between those boundaries and the boundaries derived from the description contained in the original declaration. This section does not relieve a unit owner of liability in case of his wilful misconduct or relieve a declarant or any other person of liability for failure to adhere to any surveys and plans or, in a cooperative, to any representation in the public offering statement.