Quote Originally Posted by Nekodar View Post
If it doesn't say in the log that you won the lot, or that anyone else won it, it went to someone in another alliance.

There may be a chat filter that can be disabled to see the notice for when someone in other alliance wins it, but I haven't looked for it.

Remember, you need to win not only your own alliance lot, but also over the other alliances as well.
There's also that. Your party isn't the only party rolling on that forth chest, the whole alliance is rolling on it. And from my own experience, that fourth chest is rare so you can guarantee that at least half of the alliance will be rolling on it.