Undefined index 'title' and 'body' in ApacheSolrDocument->__get()

I am using this module on a site which has content types without the standard title and body fields. When these are indexed, the following error is thrown:

Notice: Undefined index: title in ApacheSolrDocument->__get() (line 313 of D:\Projects\Foo\site\www\sites\all\modules\vendor\apachesolr\Apache_Solr_Document.php).

It appears that these fields are assumed to be present. Looking at the D6 version of the module I see this:

// use language specific stemming and so on ..
if (isset($document->title)) {
  $document->{'title_' . $language} = $document->title;
}
if (isset($document->body)) {
  $document->{'body_' . $language} = $document->body;
}

has turned into this in the D7 port:

// use language specific stemming and so on ..
$document->{'title_' . $language} = $document->title;
$document->{'body_' . $language} = $document->body;

Was there any reason behind this simplification?