The pressure's starting to get to them.
After spending the day fending off mind control, genocide, girl on girl action, little squeaky white things and an angry midget in a fish tank, the crew of the Liberator go a bit bonkers; listening to a stolen radio, catching amnesia (all of them) and stealing from an - understandably - angry motorcycle courier who seems to have lost his bike.
They're just a bunch of hooligans really.