I'd be appalled if a third of an exam was "reproduce this proof of this theorem". However, if a third of the exam is "Produce a proof of this theorem" and peopl

I'd be appalled if a third of an exam was "reproduce this proof of this theorem". However, if a third of the exam is "Produce a proof of this theorem" and people don't care about whether the proof is original or reproduced, that seems fine. Certainly, being able to proof any theorems your rely on is important. But being able to recall how any given theorem was proven in a book isn't important.