Scenario: One goes back in time say 5 years back. They have some porn of some 20-year-old on their hard drive that they totally forgot about as they take their laptop back in time. This person on the video would have been 15 in real life at the time, but the image is of them at age 20. Would the person in the video retroactivly lose their ability to consent to appear in the said image hence making the said image contraband?
It would no more constitute child porn than going back in time would make you a paedophile due to your wife retrospectively losing consent to having had sex with you in the future.
If people go back in time, can't they affect what happens? I mean maybe if you told the 15 year old not to make porn when they got older, would it still be on the file?