I think the key is that theories don’t predict the future at all.
They predict observations.
Because of my model, I expect to see X under the given conditions. If I test for X, and I do not find it, this is evidence that my model is wrong. If I test for X and find it, this is evidence that my model is correct.
This says nothing about the future or past, only what you have and have not observed yet, and what you expect to observe next (which can be about the future or past, it doesn’t matter).
I think the key is that theories don’t predict the future at all.
They predict observations.
Because of my model, I expect to see X under the given conditions. If I test for X, and I do not find it, this is evidence that my model is wrong. If I test for X and find it, this is evidence that my model is correct.
This says nothing about the future or past, only what you have and have not observed yet, and what you expect to observe next (which can be about the future or past, it doesn’t matter).