Any chance this could have happened when he was split? Maybe, akin but less than Kirk, the split was uneven? Tom Riker still seemed gung ho about being a captain, though now his chances sucked (and didn't he join the Maquis anyway? or was that a fanfic?)
That's a great retcon, and would be nice if that had been followed up on, but the episodes in season 1 all portray a gung-ho Riker, just one who kept turning down Captaincy. It wasn't until later that we discover the transporter accident, but there's no way the writer's had planned for that back in season 1.
And yes, Tom Riker does end up in the Maquis on DS9, and presumably is still at large (in canon; I've never read the novels). He's supposed to be in a Cardassian prison camp.