If it was corrected it doesn't matter if it mutated. If it isn't corrected then we have the mutation to tell us it mutated.
We have observed plants that have mutated and then been corrected in the next generation.
We observe that some areas of the DNA sequence suffer/show evidence of fewer mutations than others.
If it was corrected it doesn't matter if it mutated. If it isn't corrected then we have the mutation to tell us it mutated.
Huh?