Class 158 toilets are the devils work BNM...
And yes, I've had a few injuries in train toilets over the years.
Back in 2006 - 2007 when things at
FGW▸ were not as good as they are now. I often found that the toilet seats were not secured to the actual toilets very well, or indeed not at all.
One particular occasion on a Class 158 the train leaned around a corner and the toilet seat slid off the toilet with me sat on it...
I whacked the side of my head on the toilet as I fell. I was more dazed than injured. But had lovely battle bruises.
Personally BNM I would write a complaint letter to FGW. My reasons being that when I complained about my experience above I received 2 complimentary any network First Class tickets