I was thinking about that. I can't tilt the vise or table, but I do believe I have a sine bar around here somewhere. Maybe this would be my opportunity to learn how to use it. Although the the dovetail will be about 12 inches long when it's done. It seems likely to me that my personal skill would be the limiting factor.
He was just joking with you... a dovetail cutter cuts on the side and bottom, so you'd end up with a 45 degree dovetail even if you tilt the work piece.
Ted