Issues with unexisting items in index: entity_extract_ids() error (when used in views)

We're already struggling with the issue for several days.
As far as I understand, solr returns items that are not existing in our db already.

So, in SearchApiViewsQuery::addResults, if I do var_dump($results),
I see an array like:

array(
786 => array('id' => 786, 'score' => 1, 'fields' => array(..)),
789 => array('id' => 789 , 'score' => 1, 'fields' => array(..)), // -> There is NO such node on our website already!
790 => array('id' => 790 , 'score' => 1, 'fields' => array(..)),
792 => array('id' => 792 , 'score' => 1, 'fields' => array(..)),
793 => array('id' => 793 , 'score' => 1, 'fields' => array(..))
);

then, views tries to render fields of node=789 (which is NULL, obviously), and dies with fatal error.
"EntityMalformedException: Отсутствует связующее свойство у сущности типа node. в функции entity_extract_ids() (line 7501 in file /var/www/dev.kidmart.ru/www/includes/common.inc)."

For now, to get rid of fatal errors, I've added such code to SearchApiViewsQuery::addResults:

$nids = db_query("SELECT nid FROM {node} WHERE nid IN(:nids)", array(':nids' => array_keys($results)))->fetchAllKeyed(0,0);
      
      /****** *********/
      
    foreach ($results as $id => $result) {
      if (empty($nids[$id])) continue;

that results in incorrect views results (like, 8 nodes instead of 10 on a page) but at least doesn't produce fatal error.

Can you give me some ideas on the proper debugging of the issue?
Thanks in advance.