Doesn't mean a thing... But once your bro backed up and initiated the confrontation he became the aggressor. If something other than words had happened, he'd be in the S**t...
Unless of course as mentioned, there were no witnesses, lmao!
Don't lose any sleep over it.
If I could offer advice:
Just remember, the loudest can is usually empty!
Next time give the bird and drive on with point delivered!
If someone else gets aggressive, say nothing, do what you gotta do and leave as you came.
If caught, say even less until your attorney can talk for you!
: )