First off not sure if it is a re-post but skimmed through first 3 pages on exploits and couldn't see anything.
So as you may or may not know justice points are not looted, they are in the bag but as soon as you open the bag you get the points and the bag disappears. But here is where it gets clever (If your shoe size is higher than your IQ like me :P), if you have a unique item in there, for example "The Horseman's Baleful Blade" and you also have the item in your bags/bank it will not let you loot it and thus the bag will not disappear and you will be able to get the flimsy mask or whatever your going for (If its already in the bag) and you can still attempt to get the reins, and due to the large amount of hot-fixes lately your loot will change but you will keep the loot you already had.
Seeing as it seems complicated i will give you 2 examples.
1. You have done horseman and got a unique item you already own, leave it until the next hot-fix and you will get another item in the bag and keep the item you already had in there.
2. You have done horseman and got a flimsy mask, i am unsure how the duration works on this one so it would be safest to keep it for 6 days and loot it on the 7th just to be sure you have it, however there is still a chance of it disappearing as i have yet to try this with a mask.
Presuming horseman reins are now 5% like the brew-fest mounts that means for every unique item you get in a bag you have an additional chance to get the mount per hot-fix. With the amount of bugs at the moment i would estimate a hot-fix every 3 days, that means with 12 days left including today, if you were to get an unique in every 2 bags that would mean a total of 36 chances or an 84% chance of getting the item (That is chance of seeing the item drop, NOT having the item drop.),according to http://www.calculatorlab.com/World_o...lity/index.php
Of course the last paragraph is full to the brim with theory but i have tested the exploit itself and either i am really lucky and had the same item appear twice in a row or it works.