Did you know that if you search for Odata filter examples on boolean fields you will be sorely disappointed?
I did however, find this wonderful tidbit today:
…behind the scenes, that No has been stored as a 0. If you had said Yes, it would have been stored as a 1. SharePoint knows how to interpret this and will display these 1s and 0s as Yes and No for your convenience. Read more: http://sdt.bz/33246#ixzz2wFm8PK3c