This paper presents our system descriptions for SemEval 2023-Task 7: Multi-evidence Natural Language Inference for Clinical Trial Data sub-tasks one and two. Provided with a collection of Clinical Trial Reports (CTRs) and corresponding expert-annotated claim statements, sub-task one involves determining an inferential relationship between the statement and CTR premise: contradiction or entailment. Sub-task two involves retrieving evidence from the CTR which is necessary to determine the entailment in sub-task one. For sub-task two we employ a recent transformer-based language model pretrained on biomedical literature, which we domain-adapt on a set of clinical trial reports. For sub-task one, we take an ensemble approach in which we leverage the evidence retrieval model from sub-task two to extract relevant sections, which are then passed to a second model of equivalent architecture to determine entailment. Our system achieves a ranking of seventh on sub-task one with an F1-score of 0.705 and sixth on sub-task two with an F1-score of 0.806. In addition, we find that the high rate of success of language models on this dataset may be partially attributable to the existence of annotation artifacts.