I'm going to try and rewatch Big Bang later, but this just hit me - Where did the doctor get his Vortex Manipulator? Most of the things that cropped up during the whole wibbly wobbly timey wimey fiasco came from somewhere clear. e.g. there is a loop of events; he gave the sonic to rory, which rory put in amy's top, that the doctor took and gave back to rory, which rory put in amy's top and so on....but how did he get hold of a vortex manipulator? Wasn't River wearing it while she was in the Tardis?