This scenario doesn't have a lot to look at, but it does have have plenty of clues.
The main challenge here is identifying the gentlemen. One of them is carrying a pipe and a dagger, while the other is carrying a scalpel and a medicine bottle. Since one of them is a doctor, the scalpel and medicine bottle belongs to him. Since people generally don't carry the stuff belonging to others, we can conclude that the falling man is the doctor.
Comparing the items on the persons with the items in the backpacks makes it clear who owns which backpack. The doctor owns the backpack with medical supplies and the esquire owns the one with the tobacco. The backpacks also carry treasure. And according to the contract that each person carries a copy of, the treasure is split with two thirds going to the esquire and the other third plus any golden statues going to the doctor. This is indeed how it is split in the backpacks, further backing up the idea about who is who.
This all cements the fact that the falling man is Oberon Geller and the pushing man is Albert Cloudsley.
The falling man carries a map of the island they are on. By looking in the background, you can see two smaller islands. They match perfectly to the two small islands marked on the map. Therefore, this scene is the Horn of Thumb.
Filling in the scroll
With the men identified as well as the location, this is as simple as matching the names to what they are doing. Albert Cloudsley clearly pushed Oberon Geller from a cliff in the Horn of Thumb.