As with so many things in life, there are right ways and wrong ways to go about playing devil's advocate. The right way is to just make sure that an opposing viewpoint has been given a voice and taken into consideration before proceeding. If an individual chooses to adopt that opposing view as their own view and fight to the death for it, they are no longer playing devil's advocate.
(This message brought to you by someone who gets paid to play devil's advocate.)
On more than one occasion I stated the following. If someone's only crime is expressing a personal opinion as an opinion, I believe they deserve a lot of latitude when it comes to interpreting what they write in the least incendiary manner possible. Most people are not socially surgical pockets of eloquence.
However, the moment someone decides to take it upon themselves to direct a conversation, manipulate a context, or elevate their expression above personal opinion to social engineering, all bets are off. Such a person is required to be and should assume they will be held to the highest standards of social discourse, and the absolute limits of free-form reciprocity.
To put it simply, don't dress up as the devil and complain when people treat you like the devil. I have on many occasions played the role of devil's advocate. But I made it absolutely clear what I was doing and was nevertheless still willing to take my lumps when I did it and extend maximal patience to those that didn't recognize the tactic for what it was. And I have more years of experience dealing with that than most posters probably have with electricity, and its still a dangerous thing to do.
Lastly, I should mention this. It is not impossible to sound incendiary and yet moderate the crowd, and sound reasonable and incite them to conflagration. I've done both, and deliberately. If you don't know what you're doing, never take it upon yourself to be the voice of reason or the voice of sanity or the voice of temperance or the voice of anything other than the grey matter between your ears. Because people are not as predictable as anyone thinks, and anything else is going to be, deservedly, self-immolative.
Just say what you think for no other reason than to express what you think. Attempting anything else is volunteering to be a pinata, and honestly you'll have no one to blame but yourself.