How to prevent pager_default_initialize from getting initialized?
The easiest way would be to override theme_pager():

function MYTHEME_pager($variables) {
  if (!pager_is_disabled()) {
    return theme_pager($variables);
  }
  return '';
}


Where pager_is_disabled() is a function you write that determines the current status. You could store that info in static vars, a Drupal variable, database, cache, whatever makes most sense for your use case.