Do we really know who greg is
Maybe I'm reading too much into it but it seems as if it is left ambiguous as to whether greg is who he says he is and whether or not the spiel about his mother is real or not or even if greg is who he claims to be.
The story he mentions when he first gets into the cab makes me wonder what his true profession really is. In addition, he seemed to know how to escape from handcuffs pretty easily!
As others on here have also mentioned it seemed like he was making the whole holy water salesman story up.