Though the fact that the code is so incoherent and inconsistent plausibly makes it more impressive that they still managed to make something that works at all, and weakens the argument that "all they did was copy/translate some existing other things to Rust."

That said, it's possible that none of that code even gets executed at run time, and the only code that is actually run is some translated glue code, with the other million lines essentially dead, so who knows.