According to Hideharu Tatsumi director's column,
Subaru BRZ (#61) had suffered an accident after retiring Thailand race.
An official's winch broke, and hanged chassis fell from 50 cm height.
Although It is unclear whether this was the cause, they had a brake trouble in Motegi.
Front brake didn't work, so rear tire had locked.
They had a trouble caused by trans-axle drive train through this season.
https://www.subaru-msm.com/2017/sgt/column/tatsumi/rd8