The 20 April 1918 Motography announced that "a new Japanese-American drama, The Loyalty of Taro San, has been put into production during the last week at the Triangle Culver City studios. This is a screen adaptation of the story of the same name by E. Magnus Ingleton." A week later, the 27 April 1918 issue of the same magazine noted that director Frank Borzage was "finishing the interiors....Preparations are being made for the exteriors, the Japanese angle of which will probably be done at the Triangle ranch studio, where a bit of the orient will be transplanted." The ranch, also known as Inceville, was located in the northern foothills of Santa Monica, near where Sunset Boulevard meets the Pacific Coast Highway.
       Comedienne Maude Wayne, whom Triangle acquired when it merged with Keystone, was making her first dramatic appearance, according to the 20 April 1918 Motion Picture News.
       The title was first changed to The Honor of Taro-San, but Triangle quickly renamed the film Who Is to Blame? before its release, the 18 May 1918 Motography noted.
       Costar Jack Abbe, also known as Yutaka Abe, was a 23-year-old Japanese-born actor. This was his second film for Triangle, following Her American Husband (see entry).
       The 1 June 1918 Motion Picture News mentioned that the original Triangle press sheet for this movie included a scene in which a character was poisoned, but it was edited out of the final story.
       The 25 May 1918 Motography noted, "A Japanese tea room, oriental costumes, rickshaws and rickshaw costumes furnish settings and scenes of unusual beauty." Reviewer Joseph L. Kelly, writing in the 1 June 1918 Motion Picture News, praised Borzage's "Japanese atmosphere," noting that the first reel "is devoted to a rickshaw ride through a 'prop' street in Japan."
       According to the 15 June 1918 Exhibitors Herald, the Chicago Board of Censors demanded the following cuts: "Reel 5, subtitle: 'I'm through—any man would have been bad enough, but my own servant—'; two scenes following showing Japanese at bedroom door."
       The National Film Preservation Board (NFPB) included this film on its list of Lost U.S. Silent Feature Films as of February 2021.