From my understanding: You had a bad experience during an attempted transaction with another member. The person changed his mind and sold his item to another person at the last minute for less than what he originally was looking for. You then went on to his rep page and carried on a long conversation about the dick move (which I agree is a dick move). The problem is, people have a right to change their mind about whom they sell to and for what price. We have no control of that here at SOP. we only asked that people go through with a sale when an auction expires.
I don't agree with your action to go onto his rep thread and basically flame it. I can understand your frustration but what I would have done was this: Take screenshots of your conversation. Post in his rep thread about the dick move. Post a link to the screenshots...and leave it at that. Let people read it and make their own decision on whether or not to do business with the guy. No need to carry on the conversation from there. That's what steam chat is for.
As admins, we have a duty to step in when things get out of line. Cutting short the conversation you had on his rep thread was more than justified. Butane did the right thing and was more than fair. Consider your protest denied. Hope this helps, if it doesn't...we tried our best. There are always other trading sites for TF2.