Not all highwaymen are hostile and here's the proof!
Raven was walking via the bridge, seeing a Khajiit Highwayman in the distance. Just to be safe, he summoned his Flame Atronach but surprisingly the Khajiit didn't attack him but instead greeted him in a rather unique way. Raven didn't initiate a conversation with him but instead went on, and Khajiit remained nice and not hostile at all times.
I have no idea what was the reason for that but I'm glad it happened, I've never heard that greeting before.

That is so funny he said that! I wonder what the spell going was, I saw something in the upper right screen but didn't recognize the icon.
Maxical still gets held up by highwaymen, but not bandits/marauders/mercenaries/etc. Deer, wolves, and mountain lions leave her alone (can't remember if bear do), but boars, mudcrabs, mythic beasts, Daedra, minotaur, etc - all attack her on sight.