His talk of 35mm shows he has no clue what he's doing and has simply edited the footage to make the horizon flat throughout.
When you do such auto effects on Adobe software you are asked what lens was used to video the original footage, and there are many lenses to choose from all with different measurements. Based on their measurements the algo will make adjustments. If you don't know the original lens measurements, and I doubt this clown did, you can do it arbitrarily instead of choosing an exact measurement. This is probably what he did, arbitrarily edited the horizon to be flat throughout.
His talk of 35mm shows he has no clue what he's doing and has simply edited the footage to make the horizon flat throughout.
When you do such auto effects on Adobe software you are asked what lens was used to video the original footage, and there are many lenses to choose from all with different measurements. Based on their measurements the algo will make adjustments. If you don't know the original lens measurements, and I doubt this clown did, you can do it arbitrarily instead of choosing an exact measurement. This is probably what he did, arbitrarily edited the horizon to be flat throughout.