Yes, the expression “gross mismanagement” is one that's defined in the act, and his view was that it did constitute gross mismanagement. I don't necessarily agree with his decision that it fits the definition.
Evidence of meeting #84 for Access to Information, Privacy and Ethics in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was office.
A video is available from Parliament.