Damn, what a total douche nozzle. Did you ever call the guy's sup and tell him the deal...hopefully that POS at least got fired, but something tells me the bullshit US legal system once again did absolutely nothing good. Dude, you should be fine...it's obvious this whole incident was merely a disagreement and you didn't even hit the dude, you just brushed his hand or whatever. You didn't beat him, you didn't try, end of story. You'll be good to go...but don't seal it, like others said, makes it look like you really have something to hide - in this case I wouldn't hide any of this, all it demonstrates is what a fag this post office douche was.