My friend failed his driver's test before he even had a chance to drive. Motherfucker wrote down that my friend didn't have his ID because it took a while for him to find it in his bag, and then started telling him shit like "right of the bat we start with a MASSIVE error". Then he started asking him questions and he very pedantically twisted his words so that his answers were technically slightly inaccurate, and then failed him while also insulting him and telling him he is lucky his instructor tolerates him. He very obviously was trying to get his bribe.

It's not uncommon unfortunately. It's extremely common for people to bribe to get their driver's license, and it's also common for examiners or even instructors (who are in on the whole thing) to fail people who don't bribe them on purpose. It's probably the most profitable form of public servant bribery in Greece, along with bribing urban planning authorities etc so that people can build wherever they want and whatever they want. The worst one is probably the doctors etc who take bribes but in my experience it is not quite as common as the driver's test examiners, who basically force you to do it.