There has got to be a better way to mitigate the risk and address the issue than to shut down the entire airport for reboarding.
If anything, couldn't they at least isolate the intra-EU/overseas sections to not have to be rescreened? Unless you think the person got through, transferred something to someone else, and that has to be protected against.
Maybe gates that come down and close off sections of the terminal so you can save some people / flights / operations from having to completely shut down?
But it was “only” A/Z that were closed off. B, C and T2 were not affected... Would you prefer security checkpoints every other 100m just avoid a once (ok twice) in a decade major inconvenience?