Am i the asshole/ninja?

So we re running sm lib, having a great time, the dagger drops from the boss it has spirit and intellect on it.. I am a rogue but it is a huge upgrade for me it would replace my sword from dm. So im contemplating if i should need on it there is a mage and another rogue. The rogue is in the same situation and is waiting for me to decide and he will do the same. I see that the mage needed. I decided to need. The other rogue needs as well and gets it. We get kicked for ninja. I get called ignorant and told to google what ninja means.So am i in the wrong here?