Programmatically creating node with taxonomy term creates unexpected behavior

My goal is to create some nodes programmatically and tag them with taxonomy terms on creation. The taxonomy term may need to be created, or if it already exists, just added. I'm currently just using an incrementer as the tag, so if I'm making 5 nodes I want them tagged 0-4. Here is the code:

  //see if this term already exists and fetch it if it does
  $term = taxonomy_get_term_by_name($i);
  
  //if it doesn't exist, make it
  if ($term == array()){
    //make a new class to hold the term for taxonomy 1
    $taxonomy = new stdClass();
    $taxonomy->name = $i;
    $taxonomy->vid = 1;
     taxonomy_term_save($taxonomy);
     //now fetch it so we have it's tid
     $term = taxonomy_get_term_by_name($i);
  }
  
  //set $tid as it's returned from  taxonomy_get_term_by_name
  $tid = key($term);
  
  //tag the node with the appropriate tag
   $node->field_tags['und'][0] = array('tid' => $tid);
  
  //save the tagged node
  node_save($node);
	
  $i++;

When I run this it makes the nodes and terms if needed.

taxonomy_term_data table has the 5 terms in it, named 0-4.

taxonomy_index table has nids 0-4 properly associated with tids 0-4.

Also field_data_field_tags table has the right field_tags_tids 0-4 associated with the right entity_id 0-4.

So far so good. However when I view the nodes, they are all tagged 4. Furthermore if I click on 4, it doesn't bring up any of the other nodes, so it seems to be unique, but they all say they are tagged 4 rather than being individually tagged 0-4. Any ideas?