I guess we've all been there. I noticed it on a quilt that I finished quilting yesterday. I'm leaving it. The offending block is a log cabin block sewn in like yours, sort of turned around. But it's way bigger and is quilted with feathers. Picking out the feathers is bad enough, but then to get the feathers to fit together after.....no way. I'm not that skilled and I am not ripping out all the feathers in all six large blocks.
My mom called that an Amish error: she said the Amish believe that perfection is God's thing. So they purposely make an small mistake in every quilt, so as not to offend God. (or something like that) Since their visit to Amish country several years ago, "Amish error" have been our family's "my bad."