25% is correct from an expected return point of view.
Let's model this, shall we?

Assuming three is 1% chance of getting 5% and 0.5% chance of getting 10%:
In 200 rolls, this will yield two 5% and one 10% drop.
This would mean the equilibrium pot is at 5000: 200 roll + 200*20*0.25=1000, -(5%+5%+10%)*5000=20%*5000=1000.
This would mean 1000 coupon yield for 4000 ingots spent.
This is ignoring the free rolls, I'm not sure if those contribute to the pot, but they certainly take away from the pot. If it doesn't increase the pot, it would mean that the expected return is LESS than 25%

It is POSSIBLE, that the actual return before Monday ended up higher because they set up some kind of minimal pot line that causes a refill to say 5k even if no ingot is spent. But if that is the case, they are doing you a favor, you should not take that for granted. (And maybe the reason the whole bug occurred is because they noticed this refill is being triggered way too often and decided to reduce chance of winning to mitigate this)

In other news, if the chance of winning was 1.5% and was reduced to say 0.1% chance instead, you are getting OTHER stuff on the 1.4% that was reduced, which means with this compensation, you are getting MORE than what you SHOULD have.

For once, will you people stop complaining when they actually did something right? Being greedy is not going to help anyone, it's just going to make them feel "Fine, if you are going to complain even when we do compensate for the problem properly, we are not going to bother in the future, you are going to complain anyway"

I place half of the blame of their future post-bug inaction on everyone who complain about this compensation.

My leading theory is this:
They set a minimal pot size trigger, if the pot drop below this point, it gets refilled to 5k. (which, if true, is very nice of them)
They noticed that it is being triggered far too often (possibly due to the ratio of free vs paid roll, especially since the Aris thing happened, which might reduce paid roll enough to further aggravate the ratio)
They decided to adjust the win chance so that the refill would not be trigger as often, as it is effectively losing them money.
The adjustment was excessive and/or didn't work properly, and this happened.


My reason for this theory is that prior to Monday, it feels that the prize is won far too often for it to be sustainable at 5k(according to ptw who have made claim on the previous win rate on the thread complaining about the change), especially considering that there are many free rolls which I believe does not increase the pot but does take away from it.
If this was the case, to be honest I think we would all accept the reason if they told us about it before hand, because for all intend and purposes, the root of the problem was them being nice. But as they never said anything beforehand, the whole thing end up stinking no matter what the root cause was. It's a serious lack of foresight that made a good thing bad if this was in fact the case...

But isn't it a case of spend 1000
get 250 through % reward
and get 500 from 50 coupons
and get 750 through other drops?

If so, if I understand correctly, the bug should only affect the first one, that is the 250 through the % one, whereas you are STILL getting the 1250, so all you are missing are the 250?

Or are you saying that you received none of the other rewards that the wheel is spitting out?

Remember, it took them 2 weeks to sort out the TI/SA bug comp, and that's when everyone receive the SAME comp (which they shouldn't, but that's neither here nor there). Seeing as everyone would be receiving different amount here, the workload might be quite a bit higher. (Also, they have to actually dig their database instead of relying on screenshots. They should have digged database for the TI one too, but that's also not relevant)

Now, they probably could issue the comp to people as they go, but that might be unfair as the earliest batch might be 2 weeks from the latest, and you saw what happens when some people receive comp and others don't, people will repeatedly complain and contact them in fear of being forgotten. So they probably want to avoid that and wish to compile a full list of player to compensate before giving out anything.
They probably need to form a plan of action on how to actually send them out as well, as it's probably the first time they had to send different stuff to a large number of different people. Again, I believe they would want to minimize the time difference between when the first one is sent out compared to the last.

So in the end, this might be the slowest comp to roll out ever, because it is the most complex one they have ever had to work on.