So it seems like I've been banned for 4 days and something for Ninja in Dungeon.
Yesterday I was in a Dungeon and I needed a Foot Armor which slightly improved over my previous one.
Consequently, the player who had it bad because of that started reporting me and asked others to do so as well (even though I suggested a trade after the dungeon which he obstinately and rudely refused). So it wasn't in any case a Ninja move. Furthermore, I don't know what the player wanted to do with that loot but when I inspected his equipment, it did not seem like he needed it AT ALL (there was a player who was with me and can confirm this). And in my case it was a slight improvement but not a negligible one.
Anyway, I know that it's a silly situation and all. But I just find it unfair and I wanted to at least try to appeal the ban. Otherwise, I guess that sh*t happens.