42 It is clear from this analysis of the defences advanced by Mr Thomas that the case turns upon the findings of fact properly made with respect to the altercation between Mr May and Mr Thomas, including the events which took place immediately before that altercation, the altercation itself, Mr Thomas' state of mind at the time, and, because of the issue raised in relation to causation, the evidence relating to Mr May's departure from the scene. The evidence relating to the altercation came from five witnesses - Mr Thomas, Mr Reeves, Ms Sadgrove, Mr May and Ms Chadbourne. Because Mr Thomas admitted on the pleadings that he had assaulted Mr May, it was common ground that he bore the onus of proving the various defences which he had advanced, and for that reason, the evidence in support of his defences was led first.