Changes to $node affect the cached node

When viewing a single node in the node/nodeID page, the function node_view() unsets the teaser. If you try to reload the node using the node_load(nodeID), the node is loaded from the static $nodes array, and you find the teaser unset.
I expected the node_load() to return the full node, I worked it out by returning drupal_clone($nodes[$param]).

You can try this by reloading the node right after the teaser unset, in the node_view() function:

  if ($teaser) {
    $node->teaser = $content;
    unset($node->body);
  }
  else {
    $node->body = $content;
    unset($node->teaser);
  }
  $n = node_load($node->nid);
  var_dump($n->teaser);

I get a NULL teaser.