The worst I have done lately happen a few years a go. We where using a weed control spray that had to be Incorporated into the ground. I started out and sprayed the wrong strips. So I messed up my crop rotation. I did catch it before we planted.
Almost sprayed some Liberty corn with Lightening one year too. Caught myself just as I was starting to mix the chemicals.
Neighbor had a hundred acres of knee high corn sprayed with the wrong chemical a few years ago that way. Killed every stalk in late June. Had to replant it to corn.