Two points: (1) Hawass injects himself into everything that is Ancient Egyptian, and (2) The normal response is to deny everything since it has to be 'cleared' for Muslim orthodoxy before it is released to the public. Nothing is to be endorsed if it undermines the standard spin of the faith. There is always a 'guard' present at a dig, and that is only after permission to go ahead with the dig is given by the government. They will tell you that these precautions are to prevent theft etc., but the real reason is the preservation of the faith's tenets. Check into the games they play at the excavation of Avaris.
Maybe the muslims are scared of discovering Jewish artifacts in Egypt.