should the contractor be delayed in the final completion of the works by any act or neglect of the Authority, or of any employee of the Authority, or by any contractor employed by the Authority, or by Force Majeure and which, in the opinion of the Engineer, could have been neither anticipated nor avoided, then an extension of time sufficient to compensate for the delay, as determined by the Engineer with the approval from the Authority, will be granted by the Authority through the Engineer prompt notice in writing of the cause of delay in each case and demonstrates that he has used all reasonable means to minimize the delay