If the file does not exists - and you agree that it does not - then that log line is correct.....
From the outside you appear to have an index.php file which is serving up a meta refresh to hop to index.htm:
<meta http-equiv="Refresh" content="5; URL=index.htm">
[guessing an internal redirect going on here]
generates a 404 but this is caught and handled so I'm guessing you have a rewrite rule that is catching 404's and redirecting them. (in between there is a refer to toolbarqueries.google.com which gives a 403 forbidden but no on page error is generated). That may explain why the file index.php does not exist, but the referrer would be correct in essence if the redirect is internal.
It would help if you could share your rewrite rule(s) to be more specific.