Your edit almost made me eat my comment, but I will go further: there's nothing risky about manual memory management, as long as the compiler and/or runtime prohibit you from accessing memory you didn't allocate, adding null pointer and boundary checks (which may need runtime support to get the size of an allocated memory block) where the compiler cannot guarantee that you only access memory you allocated.

The reverse situation, garbage-collecting systems that do nothing to prevent you from dereferencing null pointers or going out of bounds, is just as dangerous as C.