msycamore said:

Maybe it appeared on re-release prints pre-ANH splice in, we don't know if the sources we have are from the first run, even though they are the original '77 film versions.

This is a good point, but even if it is true it doesn't explain how the 1982 and 1989 transfers have them, because those surely were not done in early/mid-1977 before the tear happened.

One possibility is that those video transfers were based off some sort of early IP. Then a second IP was made in later 1977 because the original one had worn out. This seems a little too convenient and if it were so those transfers would look awful due to wear and tear (the reason the original IP was retired), and it also would make little sense to use an old, battered IP (if they didn't simply junk it when they retired it...which I suspect they did) when there was a healthy, newer one at their disposal.

The final possibility I can see is that those transfers are based off of a 1977 archival print made before the release, as often is done, before the tear occurred.

I have a hard time swallowing this at first because it seems pretty convenient that every single 1977 source managed to record the tear. But it could be true. We know they had to make at least a second IP, and if it were to be done at any time it would have been mid to late 1977 when the film was at it's peak of popularity and print-circulation. If the bootlegs were recorded in September or so, it could have been for a late batch of prints that were struck from a second IP made from a now-battered original negative that now had the tear. Meanwhile, the 1982 video used a print master made in 1977 when the film was first finalized and thus before the tear was present.