With the rapid progress of RFID security technologies, the international standard group ISO/IEC JTC 1/SC 31 is developing a few security technologies for RFID systems. One of the initial proposals is' ISO/IEC working draft (WD) 29167-6. Recently, Song and others stated that Protocol I of ISO/IEC WD 29167-6 is vulnerable to a malicious adversary. However, their analysis' comes from a misunderstanding regarding a communication parameter called Handle. In this letter, we point out that an adversary cannot obtain any sensitive information from intervening in Protocol 1.