Fallout New Vegas: NCR attacks me during you'll know when it happens?

ok so im on the mission stated in the tittle. i sold some guns to the gunnrunners and it was fine. i go to the ranger and he tells me to meet him on the balcony and what not. i go out there and everyones friendly but one ranger standing in the back. he shoots me and boone than attacks him with a chainsaw and than everyone attacks me. its a flippin sack of skittles and im getting mad.