If things end in an amicable, understanding way, then I would say yes, keep them as a friend, unfollow if you must. But things usually end fairly poorly, and if you're at the point of debating unfriending - it's probably not a friendly ending.
Give yourself a few days, to mull it over if you wish. But if they're being disrespectful and otherwise a ***** to you - **** it. If you're done with them - be done with them. I've had a couple girls try to mind**** with me purposefully. One texted me asking why my married best friend didn't reply to a text she sent a couple hours ago - all concerned over him for whatever reason. I replied normally, answered her question, whatever. I told my friend, he thought it was weird. Few days later, texting him in the morning (after I hung out with him at his house, seen her going out with his wife for her bday drinks, being snotty to me that night), saying he should make her breakfast and all this other ****. This was on top of a hundred other bs things over the year then.
Waited a week or so, blocked her on fb, phone. Didn't stop her from being more directly flirty, cleaning my collar of something, dancing close over the next half year. Culminated in her asking me out for coffee sometime (she seemed to be waiting for me to ask that). Said no thanks, and I believe she overheard me saying to someone I'd prefer to tell her to f off. She still flitted around my work area unnecessarily.
Morale of the story. If you're done with them, be done with them.