So... they used the Democratic poll book (even though it was a Republican primary) on 6/24 to prevent illegal double-voting, and then went ahead and allowed people to illegally double-vote anyway and recorded the fact that it had occurred (instead of just using the Republican poll book so that they could plausibly claim honest error and avoid creating an obvious written record)?
My brain hurts.
There is no prerecorded party affiliation in Mississippi, so all the poll books have exactly the same list of names. The way a person's choice in the primary is recorded is by choice of book to record it in. Republicans are listed in the Democratic poll book (so they can cross over), and Democrats are listed in the GOP poll book (so they can cross over).
What is forbidden is to vote for one party in the primary, and a different party in a runoff. If the GOP poll book was used to record 6/24 votes, that can STILL be compared against the same name in the DEM poll book used on 6/3. Either way it is an obvious written record.
Heh. Well, you will never go wrong if you overestimate human stupidity.