It is not ideal, but, you could use a smaller pin. It looks to be a 1/4 inch pin? Correct? If so, use a 1/8 inch pin but place it as far forward as possible. It would give you a little more room to the rear of the knife edge. You can attempt to dremel out more material from the front of the hole. If it is hardened I would not attempt with a regular drill bit.
As a suggestion only. Prior to heat treat on your next knife. Drill a few more hole in the handle. On this handle it could be a 1/2 inch or so. Maybe a row or two - three to five deep on each side. Stay away from the edges. The reason for my suggestion is it lightens the handle and gives the epoxy better holding between the two scales. I hope that makes some sense to you.