Node 'title' and 'content' classes are printed twice

Hello community, it's the first time I report something so tell me if I'm not doing it right...

I noticed that the function tao_preprocess_node(&$vars) have a strange behaviour.

In fact,

$vars['title_attributes_array']['class'][] = $vars['hook'] . '-title';
$vars['title_attributes_array']['class'][] = 'clearfix';

And...

$vars['content_attributes_array']['class'][] = $vars['hook'] . '-content';
$vars['content_attributes_array']['class'][] = 'clearfix';
$vars['content_attributes_array']['class'][] = 'prose';

...print their classes twice. I tried on a fresh install with the last drupal core and activated tao only and got the same result on local and distant server.

How can I fix this ?