Sorry, I’m not a native speaker, could you explain this « you know when you’re not rolling » thing? And what dealings does it have with Gillian? Does it mean there won’t be txf11? I don’t get it.

No, I understand it as a joke, because the girl was a XF fan, and David joked she asked him to call Gillian off camera – “call Scully when they’re not rolling”. That’s how I understood it, but I’m not a native speaker either, though.