This paper describes the submissions of the Natural Language Processing (NLP) team from the Australian Research Council Industrial Transformation Training Centre (ITTC) for Cognitive Computing in Medical Technologies to the SemEval 2023 Task 7, i.e., multi-evidence natural language inference for clinical trial data (NLI4CT). The subtasks address the problem of (i) determining semantic relation label between premises from clinical trial report and a statement (whether the relation is entailment or contradiction) and (ii) identifying the relevant parts of the premise that justify the label. We approach the evidence retrieval problem as a document retrieval and sentence similarity task. Our results show that the task poses some challenges which involve: dealing with complex sentences and domain-specific vocabulary; incorporating information from text and tables; and numerical reasoning.