I have checked the change log and the original title was "Bus driver kept my change", so no mention of the word "dishonest" in there.
I suspect his comment was tongue-in-cheek.
I am surprised that you can non-issue the ticket after all that time tbh. I thought non-issue could only occur before a specified number of tickets were issued after the ticket in question.
It depends on the system, but yes, it may well not be possible to do (in which case I would retain the ticket, write an explanation on it, then include with cashing up).