I'm unable to tell anything because the photos are too small. When taking photos of paper money or coins, it's best to get a clear shot, crop out the background, and click on Full Size when you upload them.
I will say this. It's as they were washing the plates after a problem with the printing press. They did not clean the blanket wash off, and it bled into the paper before the press was restarted. On the very next startup, then the bleed-through was done before the next startup andthe bleed through had dried. Then the first printing of the reverse would have had this done. I was a printer a very long time ago. Set type by hand and also did offset printing. Today it's all electronic stuff.
That is not government ink. The serial number on the bill would be in the middle of the run and the BEP does not clean in the middle of the run.
So, You are saying that if they have a breakdown that they keep running. Ok, so how do you know about how it runs? All things mechanical has breakdowns. Nothing is perfect. So, you buy a mechanical object and you say it never breaks down. Then you are saying all things are perfect. Do you understand which is the first run, 2nd run, 3rd run, and then the triming? So, if they have perfect runs, then they would never need any "Star Notes". Correct?
You need to research how bills are printed. It's not the way you think. In short, so many bills are printed in a run. Each bill has its own 8 digit serial number. It's how the BEP tracks them.
Is that a fact! Have you been to the BEP? Have you talked to any of them? I have been to both. I have discussed such to some and I have found out stuff you could not. I have some of their emails so I can ask them questions about some of the problems. So I disagree with your opinion. I hope you have a great day.
Just wondering "Nut" How long, if you have collected? I have been collecting coins since 1953, and currency since 1963. So, I would like to know about your experience. I cannot wait for your response?
You asked one question. I answered truthfully. What don't you understand? Please don't answer. I've stated my opinion and you disagree. Fine. We are both entitled to our opinions. I stated we agree to disagree but you continue to argue. I will not be responding. Thank you and good night.
Going back to the OP images. The staining came after the bill had been folded. I don't see a way it could have left the BEP with that pattern.
I agree with @Collecting Nut, the bill was folded and then became wet and either the wallet or material it was in contact with stained it. To over look the obvious of the unstained folds is to assume much, and we all know what assume means, don't we?