pfff, this is starting to get boring...
You assume that there are no forces working between the particles when the Big Bang occured and that therefore they all fly away equally spread in all directions.
That is a stupid assumption to make. Nobody knows how it went exactly with the Big Bang, if it even was there of course. But it is certain that there were forces working between the particles. Gravitational forces for certain and who knows how many others. We don't even know what kind of particles were there. There could have been magnetical fields, electrical fields and who knows what other things that influenced the direction and speed of the particles.
Assuming they all spread equally is not very smart, if not plain stupid.