Although of course it's not known that the creation of particle-pairs is really causeless. (One can say it's caused by the laws of physics, or something, but of course that's not a good line for the Kalamitous to take because it rather undermines their subsequent claim that "conceptual analysis" of the cause of the universe shows that it must be a person with, surprise surprise, roughly the attributes Christians traditionally ascribe to their god. :-) )