http://pokemondb.net/pokebase/85839/pros-and-cons-of-garchomp-vs-dragonite
On the above question I saw my answer had been selected. I thought chaitrak changed his ba but turns out this wasn't the case. While mine was best answer, there was nothing that said "selected by ____" which I just assumed meant you got rid of the thing finally. So either a glitch of the site or someone found a way to select best answer without it saying +selected by _____".
Sorry I couldn't give you the the actual thing, chaitrak rechanged best answer. Hopefully my word will be all you need to find out stuff if you don't already know.
I did reset some stuff last week, which was related to that, so it's possible that removed the "selected by..." text.