I got an excerpt with an incomplete tag at the end:
TheĀ <a title="Oral mucosa" href="/wiki/Oral_mucosa">oral mucosa</a> is the<a title="Mucous… </div>
Could be a bug in force_balance_tags - I added a little fix after that call:
$text = trim(force_balance_tags($text));
//DKK: Remove partial tags at the end - not sure why this isn't handled in force_balance_tags
$last_open_pos = strrpos( $text, '<' );
$last_close_pos = strrpos( $text, '>' );
if ( $last_open_pos > $last_close_pos ) {
$text = substr( $text, 0, $last_open_pos );
}