No one thought that Irene could be a fish either (even Stewart couldn't see how it could go NE with the strong high in place)- turns out there was a weakness and it went off to sea. Models consistently showing fish here so I'm feeling much better about T.D. 17 not being a threat.
If more models start showing what the NOGAPS is saying, then I might change my mind but for now I see no reason why this isn't going to be a fish.
Plus there's this from the NHC 5 PM:
THE INITIAL MOTION IS A STILL SOMEWHAT UNCERTAIN 310/8. STEERING
CURRENTS REMAIN UNUSUALLY WEAK FOR THAT PART OF THE ATLANTIC...AND
THE CYCLONE IS EXPECTED TO MOVE RATHER SLOWLY NORTHWESTWARD AROUND
THE SOUTHWEST SIDE OF A WEAK MID-LEVEL RIDGE FOR THE NEXT 3 DAYS...
WITH PERHAPS A MORE NORTHWARD MOTION AFTER THREE DAYS TOWARDS A
WEAKNESS IN THE RIDGE.
Sounds like a fish to me

The one possibility I can see is an Isabel like track where it goes NW for days and then turns wnw and W.