I'm fairly certain that person said something more than a few times to Sean and he just lost it. However, on a place like Twitter, where what he says makes such a wave with others, I think it would have been best that he respond with something less negative. ONLY because it shows that he/she got to you and you are above that Sean, bb.
Also, he typically is more funny but I think he bit off more than he could chew with his recent activities, but he'll catch his step. Sean is a very dedicated guy. He's an observer and he knows how powerful words can be. If this ends up being a set-back he will only grow from it, but in my opinion it isn't wise to resort to something 'on their level.'
Rise above bb. You can and you have.
"Let me live in you..." ~ John Lennon