This just in from the FIM: (FWIW: Wikipedia essentially defines terbutaline as an asthmatic inhaler.)

QMMF Endurance World Championship Anti-doping controls

Following an anti-doping control carried out during the Suzuka Eight Hours, one sample was found not in accordance with the FIM Anti-Doping Code. The sample of the Australian rider Russell Holland, racing for the Team Sakurai Honda 2, contained terbutaline, a substance which is subject to a Therapeutic Use Exemption (TUE) provided for in the FIM Anti-Doping Code.

However, the administrative procedure required for issuing this authorization by the FIM was not respected by the rider, and thus the International Disciplinary Court (CDI) decided to disqualify the team from the results of the event (team not classified) and to pronounce a suspension of one month to Russell Holland as from the notification of this decision, for not having respected the procedure established in the Anti-Doping Code.

An appeal may be lodged to the International Tribunal of Appeal (TIA) within 5 days as from the notification of this decision.

Neither prohibited substances, nor their metabolites, nor markers nor a prohibited method were detected in the other samples tested.

The other riders tested were: Chojun Kameya (JPN), Shinichi Itoh (JPN), Yusuke Teshima (JPN), Kosuke Akiyoshi (JPN), Yukio Kagayama (JPN).