High Performance Work Systems (HPWS) research is based on the search for the most suitable bundle of complementary practices appropriate for the organisation and its operating environment. We examine the contents of a HPWS in organisations seeking impeccable safety and reliability as their foremost ‘performance’ outcome. We propose a ‘High Reliability HRM’ framework, and examine the degree of implementation in a three case study of Australian state emergency services organisations. The findings highlight HRM practices inconsistent with the framework, and illustrated by rich interview accounts, we detail associated negative implications for employee behaviour and attitudes. We contribute to HPWS research by empirically examining how reliability-seeking organisations conceptualise and implement HRM systems. This study emphasises how inconsistency in HRM practice bundles can pose a threat to reliable service provision, a critical finding for emergency services and reliability-seeking organisations more broadly.