> Also the above will not compile.

It compiled for me (after changing NULL to nullptr).

> Because compilers can actually detect if you set a pointer to nullptr and then use it.

Apparently it didn't.

> Here, you didn't use it so maybe the compiler won't complain. But in the general case yes it will complain.

That's incorrect, there's a use of the nullptr.

> You call some unsafe code that directly interacts with memory.

I don't see something explicitly declared as unsafe from the source code alone. It looks like a normal pointer dereference to me.