This may be a known bug already in other instances, but it is easily reproducable with a team of Valkyrie Scouts. If they attack each other, it will create a string of attacks that will continue on even after all but one is dead, essentially guaranteeing a wipe. Is the action queue meant to keep going after creature death?
Most effects in battle actually happen at the same time, so this is the way it is meant to work. It just looks a little weird sometimes if a ton of actions are queued up.