so why didn't you do it?
You couldn't have been charged with anything, because he came up to you, pushed you along and then spat on your face, I think that is enough grounds for self-defense..
Moreover, if Derek Anthony has AIDS (Lets assume he does) and happened to have an open mouth sore that was oozing large amounts of blood (maybe serosanguineous fluid to clear fluids), by spitting on your face (in particular, the membranes located in your eyes) you could now be the proud owner of the HIV virus.
I'd reconsider everything that happened and wage a large-scale lawsuit or something to that nature..