It's obvious why he failed so not sure why he had to ask when he told us.
Anyhow, even though I passed my car test when I was 17 first time, it took me 3 attempts to pass my bike test. Mainly becuase I did not practise enough, at 20 something, the option of riding a 125cc hairdryer where I could not take passengers etc.. or to use my car. The night before my final test, I spent a few hours riding around the side streets practising, this was tedious but worth it in the end.
At least here you can ride a big bike with L-Plates.