Lucy Neatby made Great cable fix on a finished sweater! with:
Q&A with Lucy Neatby
Seeing this project made me realize that to do a fix like this you had better have the correct number of rows in your "error" or you'll not be able to fix it. I guess this means there are SOME errors that can't be fixed. For example: if the mixtake in the cable had included an added (or a missing) row it couldn't be fixed.
Lucy Neatby answered:
You are partially correct there are some errors that are cannot be fixed. However, if the extra/missing row was really noticeable (which seems unlikely), you could leave out one row when making the repair, (just darn in the ends or add an extra strand and darn), but you would need to do this across each cable on that row. You could also graft on waste yarn and drop the entire lower piece, add or subtract the row and re join.