SAN FRANCISCO — When news broke this week that Liu Qiangdong, the billionaire founder of the online retailer JD.com, had been arrested in a criminal sexual misconduct case while on a business trip in Minnesota, the local police were vague about the details.On Tuesday, the Minneapolis Police Department released its report on the case and said Mr. Liu was arrested Friday on a rape allegation.Mr. Liu, who goes by Richard Liu in the English-speaking world, was freed on Saturday without bail and has returned to China. At the time, the police did not offer specifics beyond using the term “criminal sexual conduct,” which covers a range of…