Short answers, pulled from the story.
Lord Lytton led a team that included Major-General Frank Ross McCoy from the United States, Dr Heinrich Schnee from Germany, Count Luigi Aldrovandi Marescotti representing Italy, and General Henri Claudel as the French delegate. The group arrived in Manchuria during spring 1932 after being sent in December 1931.
The report stated that Japanese army operations could not be regarded as legitimate self-defense because the seizure occurred without authorization from the Japanese government. It concluded that the State of Manchukuo had no general support locally or from China and was not part of a genuine independent movement.
The commission arrived in Manchuria during spring 1932 after being sent in December 1931. They spent six weeks traveling through the region in early 1932 to examine train attacks and collect evidence from eyewitnesses who witnessed events after the 18th of September 1931.
Japan gave formal notice of its withdrawal from the League of Nations on the 27th of March 1933 following the release of the report. The Japanese government extended official diplomatic recognition to the puppet government of Manchukuo in September 1932, which occurred before the official announcement of findings became public.
Great powers never invoked Article 16 of the Covenant to mark Japan as an aggressor because they refused to levy economic sanctions during the Great Depression. Western nations were reluctant to damage their own economies by sanctioning another great power, leaving the policy largely as appeasement without any enforcement mechanism.