stdio to terminal after close(STDOUT_FILENO) behavior

I am wondering why uncommenting that first printf statement in the following program changes its subsequent behavior:

#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

int main() {
  //printf("hi from C \n");

  // Close underlying file descriptor:
  close(STDOUT_FILENO);

  if (write(STDOUT_FILENO, "Direct write\n", 13) != 13) // immediate error detected.
    fprintf(stderr, "Error on write after close(STDOUT_FILENO): %s\n", strerror(errno));

  // printf() calls continue fine, ferror(stdout) = 0 (but no write to terminal):
  int rtn;
  if ((rtn = printf("printf after close(STDOUT_FILENO)\n")) < 0 || ferror(stdout)) 
    fprintf(stderr, "Error on printf after close(STDOUT_FILENO)\n");
  fprintf(stderr, "printf returned %d\n", rtn);
  // Only on fflush is error detected:
  if (fflush(stdout) || ferror(stdout))
    fprintf(stderr, "Error on fflush(stdout): %s\n", strerror(errno));
}

Without that first printf, the subsequent printf rtns 34 as if no error occured even though the connection from the stdout user buffer to the underlying fd has been closed. Only on a manual fflush(stdout) does the error get reported back. But with that first printf turned on, the next printf reports errors as I would expect. Of course nothing is written to the terminal(by printf) after the STDOUT_FILENO fd has been closed in either case.

I know it's silly to close(STDOUT_FILENO) in the first place here; this is an experiment I stumbled into and thinking someone more knowledgeable in these areas may see something instructive to us in it..

I am on Linux with gcc.