Why is my [`hook_node_validate`][1] implementation being called when I try to delete a node through the node editing form (by clicking the delete button at the bottom of form)?  Validation fires and then my node doesn't get deleted which is not what I want.

Documentation says: *Perform node validation before a node is created or updated.*  
Is deletion considered an "update" to the node in this case?  

  [1]: http://api.drupal.org/api/drupal/modules--node--node.api.php/function/hook_node_validate/7