Your Update server behavior binding is set to the form field value. Instead it should be set to the "Server File Name" in the file upload bindings.
This:
$UpdateQuery->bindColumn("pic", "s", "".((isset($_FILES["pic"]))?$_FILES["pic"]["name"]:"") ."", "WA_DEFAULT");
Should be:
$UpdateQuery->bindColumn("pic", "s", "".($WA_DFP_UploadStatus["WA_UploadResult1"]["WA_UploadResult1_1"]["serverFileName"]) ."", "WA_DEFAULT");