They claim that they were. They had several bladder tanks (a variety of new and old) full of fuel circulating at elevated temperatures for months....with no leaks or degradation to the materials.
Yup.....and when I worked in industry we farmed out R&D engine testing to Rouch. They have very capable engine labs for testing....I'll bet far exceeding George's rigs.
Meh....all the flub-hub over the leakage. Like a AvWeb commenter said....it's probably some kids chocolate ice cream cone rubbed on the bottom of that wing. Nothing to see here folks.....;)