Just thought I'd post a quick confirmation that Fatheads really are phantom-power safe... at least in the short run.
My 15 month old daughter made a visit to the studio last night. I was setting up a mic when my wife informed me that she was "pushing buttons." I came over to inspect her handywork, and was horrified to see that she had chosen a phantom power switch on the preamp that the Fathead was running through.

I powered it down and then gave a listen. Much to my relief, it seemed to be fine. Probably wasn't on for more than a minute or two... but I've heard that that's enough to toast a ribbon.
Phew.