Why doesn't "git log -- foo" work for deleted file foo?

Question

My repository underwent changes such as:

1. ...some unrelated commits...
2. Commit new file foo with 100 lines of content
3. ...intervening commits, some of which touch foo...
4. Insert the contents of foo at the top of an existing file bar and git rm foo in the same commit
5. ...more unrelated commits...

Now I want to see the log of deleted file foo. Everything I've read, including on SO, says I should be able to git log -- foo, but that command produces no output.

If I find the commit that includes deleting foo I can git log 1234abcd -- foo and see its log, so I think my path to foo isn't the problem. Also note that git merge-base HEAD 1234abcd outputs 1234abcd[...], so I think that should prove the commit is reachable from HEAD. Note that there is no file foo in my working tree (obvious, since it was deleted). Using Git 1.7.1.1 on OS X.

Why doesn't git log -- foo work for me and how can I fix it? Thanks!