Implementing redirection on node viewing without affecting solr search indexing
How about doing this in hook_init() instead, eg, something along the lines of...

function YOURMODULE_hook_init() {

   $mgo=menu_get_object();

   if (!empty($mgo-&gt;type) &amp;&amp; $mgo-&gt;type=='THE_TYPE_YOU_ARE_LOOKING_FOR') {

      if (!arg(2)) { // eg so we ignore node/###/edit etc
        if (!empty($mgo-&gt;field_THE_FIELD_YOU_ARE_REDIRECTING_TO[0]['value'])) {
          drupal_goto($mgo-&gt;field_THE_FIELD_YOU_ARE_REDIRECTING_TO[0]['value']);
        }
      }
   }

}


Caveat:  I've never used apachesolr, so you may need to wrap this with further logic to make sure you are running when a user actually goes to the page, eg, arg(0)=='node' and is_numeric(arg(1)) kinda stuff.

ADDITION:

You might be able to just check args inside nodeapi() as well, eg:

if (arg(0)=='node' &amp;&amp; is_numeric(arg(1)) &amp;&amp; !arg(2)) { 
  // do your magic
}