Thanks Bruce. There is a Creek captain also by the name of Gordon and Adair was in the Creek Nation. However, Adair's choice of words sound like this 'Gordon' was passing through and also, as if they might combine forces to scout. By this time, the fords on the Arkansas were well picketed by Phillips so Quantrill et al, on at least a few occasions, were crossing well above Ft Gibson. After the Baxter Springs "massacre", I think Quantrill crossed the Arkansas 18 miles above Ft Gibson on his way south.
This is a lot of speculation to say it is at least possible that this was Si Gordon and company and it's worth looking for more evidence.