Sounds more likely - I have a vague recollection of you almost turning back on yourself at a 'Y' junction.
That would be the one. It is a naughty right turn there. We are supposed to go on to a turning circle, but if there is a break in the traffic I do the right turn.
Coming down the hill, the same applies but I nearly always take the left unless there is a police car about. It is perfectly safe on a bike, probably safer than crossing the A646 twice. I often see cars going from Hebden Bridge towards Todmorden jumping red lights at that junction so there is the potential risk of being hit by doing the 'right' thing and avoiding it by doing the 'wrong' thing!
It might even have been before you had the singlespeed, which will be a few years ago.
It would have been but I wouldn't have attempted a route like that on singlespeed anyway. It always amazes me what riders like PP can get up on fixed but singlespeed doesn't have the benefit of the chain driving the cranks through the deadspots at the top of the pedal stroke. That is the killer - it is fine once the crank has gone about 15 degrees beyond the top point and one's weight can be brought into play.
@Pennine-Paul, who definitely was on a fixed/singlespeed, may have been on the ride.
I think me and him took the flat route back towards Todmorden, although he may have peeled off to go home.
I'm sure it would have been fixed. He only did one of my rides with gears and hated it so he changed his bike back to fixed! I can't remember him riding with a freehub/freewheel any other time.
He would have gone to Todmorden with you, then turned left and headed back towards home in Greater Manchester.