So, given that some people do like shooting cops there's probably some advice required about what to do if you don't want to be in the OPs situation. Right now I'm sitting on a ship with a 1.5 billion bounty, with only 1.1bn in the account, so I am also flying without rebuy when I'm in that.
I prefer one of two methods, the first is the big heavy tank such as a Vette, Vonda or Cutter, not a T-10. If you're going big you need good shields, preferably prismatics. Reinforced engineering and lots of heavy duty HRPs and armour are also required.
The other is the cheap manoeuvrable hull tank such as the FAS, Clipper or Chief/Chally. Again, lots of armour and heavy duty HRPs. Shields should be set up for quickest recovery following being broken.
Biggest things to keep an eye on are of course the ATR announcements. If you hear that, jump out of the system (you did have a pre plotted route set up didn't you?). The second is watch the hull. Set yourself a comfortable limit- 30% should be fine with a well engineered ship and go as soon as you hit this. In both cases, go, don't finish that last kill, get out and what happened to the OP won't happen to you.
Then just find a station not controlled by the faction you've been shooting up, take a breath, repair, rearm and go back to rip and tear again.