It was obvious the man with burned scars was Saul. I even explained exactly what happened at one point. He was frozen, and the island was set on fire, so the ice melted. Then, he went into hiding because he was the other survivor of the incident. Nobody knew where he was because he went to Elbaf and it has the strongest army in the world. He took sanctuary there.
Lots of other people were like "maybe it's Xebec" lol
This an extremely important chapter. Saul and Robin are likely going to discuss the research of O'Hara and it will change the perspectives of the Straw Hats. I'm slightly annoyed it happened so easily tbh.