Several accounts exist regarding the cause of the altercation in which Richardson was killed. Louis G. Perez, Ph.D, Professor of Japanese History at Illinois State University, in "Japan at War: An Encyclopaedia" (2013), presents the following: per one account, Lennox and his party were turning their horses around to yield the road when the Satsuma retainers attacked preemptively to maintain the order of the procession; this arose from "the language barrier and the retainers' anti-foreign zeal". Alternatively, it was claimed, Richardson and his cohort forced his way into the procession and were attacked by the retainers, outraged at the disrespect to their lord. In any case, the incident "reflects the widespread anti-foreign sentiment that had emerged among many Japanese people since the country was forced open in 1854."