He was predominantly interested in issues relating to returned soldiers, also opposing any attempts to decrease defence expenditure and supporting the local manufacture of aeroplane engines.

The jury dismissed the petition on the grounds of connivance by Hall, but found that misconduct had occurred; as a result the presiding judge did not award Foster his legal costs.

[1] In July 1923, he was granted two months leave of absence to take a health trip to Queensland, with Albert Gardiner advising the Senate that he was suffering from shell shock and was unfit to perform parliamentary duties.

[4] In October 1924, it was reported that the Confidential Finance Company had initiated lawsuits against Foster in multiple states for writing bad cheques.

[5] In the session of parliament running from June 1923 to October 1924, Foster made the least appearances of any senator, attending for only six out of 95 sitting days.

The Attorney-General of Tasmania stated that bankruptcy proceedings would be brought if no payment was made, which if successful would result in his seat being declared vacant.

Foster became a disciple of Robert Brodribb Hammond, a Christian evangelist and social reformer who was a leader of the temperance movement in New South Wales.

The Hobart Mercury published an interview with Foster about Hammondville in 1935, describing him as "a zealous spokesman for social justice, and a diligent student of ethical, psychological, and economic problems".