Luckily, Rex's heads-up was enough to get us outside in time to beat Mr. Fox to the punch. Big atta-boys and belly scratches were given, and the head of security went calmly back to his post (the front porch) to continue his watch. :)
I have to say, even though Rexy isn't a purebred Pyr, he has been a kick-ass farm dog and companion, as promised by the wonderful people at the Great Pyrenees Rescue Society. We are so thankful to everyone who lobbied on Rex's behalf to rescue him and find him a good forever home.