from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An erroneous correction; a mistake in correcting a previous mistake.
from The Century Dictionary and Cyclopedia
- n. A false or erroneous correction.
mis- + correction (Wiktionary)
Walter Scott was called in council, and offered one miscorrection which still blots the page.
Records of a Family of Engineers
Looks to me akin to a double negative, or a hasty miscorrection. "who wrote on leaving a kindly note" and "who on leaving left a kindly note" both work.