 He became a master at his old school, the Sydney Grammar School, and continued there for 11 years.In 1910 he again stood for Parramatta, this time as a Labor candidate with the encouragement of Billy Hughes, but was defeated, and shortly afterwards obtained a position in the Sydney land tax branch of the Commonwealth Treasury.In 1913, Hughes asked O'Reilly about the views of his brother-in-law, Albert Piddington, on states' rights.