Personally, I'm not a big fan of trash talking, ESPECIALLY in the middle of an event. Now, if it's friends and I, or people who know me, that's a bit different story, but in most cases, I let my performance do the talking and save my celebrations for the end.
I get this was at the end of the Buffalo/Scar match, but it wasn't the end of the tournament. I liken this to a baseball player over celebrating a home run in the 4th inning, or a football player over celebrating a sack when his team is down by 14 points. I don't really like it in those situations and I didn't like it here.
If Buffalo felt Scar's tweet was "discrediting" his win (I personally didn't read it that way) he could have addressed the situation with Scar before the event. Perhaps Scar should have sought Buffalo out and attempted to clear the air.
In the end, though, I personally like the "act like you've been there before" attitude and holding off my celebrations until I've actually won the event I'm competing in.