Before I sew the rows together, I generally lay the pieces out and leave them for a bit. Next time I go look at the layout, I have a clear mind and I usually pick out the "odd ones."
If it is a directional top, I mark the sides of the rows that need to be sewn together. It is easier to check each set of rows than end up with a wrong row and the top done.
In the meantime, better make friends with your ripper.