They weren’t donating their time. Writing tests was part of their job. They just made the questions a lot harder and more based on practical knowledge. Rather than just recalling information found in the book you had to apply the information to answer the questions.
Not really a lot of the teachers at the tech school I went to did it that way and I know for a fact they weren’t getting paid well at all.
Then you’re lucky they had the freedom to donate their time like that.
They weren’t donating their time. Writing tests was part of their job. They just made the questions a lot harder and more based on practical knowledge. Rather than just recalling information found in the book you had to apply the information to answer the questions.