WP Query: How to get posts from a specific author OR posts with a specific meta value

I found some hints here: Can i merge 2 new WP_Query($variable) ‘s?

So i created two separate queries and merged them into a new array:

$wp_query = new WP_Query();
$wp_query->posts = array_merge( $query1->posts, $query2->posts ); 

foreach($wp_query->posts as $post) :
setup_postdata( $post );

And then the usual stuff.