Me and a friend were playing the game, and a blue chestpiece perfect for my juggernaut dropped. Needless to say, I needed it, but my friend pressed need without realizing it. They apologized, but it was no use. Since they needed and got the item, it was completely impossible to ever get that chest piece without hours of grinding or doing the heroic, which was nearly impossible for us.
TL;DR: Trade and Mail limitations should have exceptions for gear that was won in a roll.