The backdating is trivially detectable unless you manage to get the database operations to happen the wrong way around, which is why the whole "holding a packet" thing has to happen. But part of the reason for the blackout period is to account for the possibility of that kind of thing happening anyway.

If you have to fake the issue time by five minutes, then 1) the described method is probably infeasible anyway because the connection to the database will time out while the packet is held for multiple minutes, 2) the ticket issue date and audit date on the database event will vary by at least five minutes which makes it obvious that the ticket was improperly issued.