On the first look, it seems that there is a mistake in the datasheet. But, please note that these parameters are tested at opposite conditions, i.e. tLZOE is tested at high Vcc, low temp and fast corner whereas tHZOE istested at low Vcc, high temp and slow corner as the former is a min. spec.and the latter is a max. spec. So, at any given temperature and voltage, the design is guaranteed such that tHZOE is less than tLZOE to prevent bus contention.