There are no guarantees in life, but ...
If government officials follow established procedure, and use government computers (only) and stay behind firewalls, and get government-mandated patches and updates in a timely fashion, and go through appropriate government Help Desks when trouble appears ... if these basic steps are followed, then disaster (however you define disaster) becomes less likely.
However ... if you hire some schmuck to set up a secret server in your bathroom, and if you rely on a staff with no IT skills at all, and if you make stuff up as you go along ... you just never know what’s gonna happen to your data. That’s the price you pay for going outside the established process.
You left out:
The Weiner link ...
Podesta opening an attachment which requested him to setup a new password for his email account.