You're supposed to be a scientist, Rex. You ought to know the TARDIS shares a number of properties in common with the Barge. She may have been able to resist floods and breaches, but docked to the ship as she is she's still invariably connected to it.

At the very least, very least, your passion to be rid of this place led you to ignore very basic scientific principles you should have looked in on. -And good-byes. They're not just parting. They're letting someone know that you actually meant something to them. That's why they're difficult. That's what they're about, telling someone that you care enough about them that you're not casting them aside and they're worth a spare fault.