I think this is just a publicity stunt.
Looking at this from a third person perspective and seeing that this guy is still betting I guess that Primedice isn't in trouble for now. At least not yet. If this is really happening the hard part for PD should be paying out this guy. That's a great way for us all to see if Primedice is really as big as it wants us to believe it is.
But all this makes me somewhat suspicious too.