I was reading a section from my textbook about tautomeric shifts, and it seems to suggest that there are some mutagens that can be directly responsible for the phenomenon. The section is mainly describing spontaneous mutations as opposed to induced mutations, and examples of mutagens are mentioned. However, the author explicitly states that the sort of changes made to DNA due to spontaneous mutations also occur at a higher rate during induced mutagenesis.
If a tautomeric shift can occur due to mutagenic activity, is it possible for the mutagen to undo and "correct" the mutation by reversing the shift? If so, what kind of chemicals or physical mutagens (e.g. radiation) would be involved?