I'm gonna add a 3rd: it doesn't actually "understand" the program it produces. If you don't understand the details of the program, and attempt to fix it based upon that misunderstanding, it will happily introduce the bug you just asked it to introduce.

I noticed it will assert itself when it comes to data that is more common knowledge. For example, I tried to convince it that forests contain a lot of sand, and it wouldn't budge - the closest I got was that there's sometimes sand by rivers/etc in a forest.

But when it comes to programs it writes, it will acquiesce to the human driver, bugs be damned.