I used to live in Oregon, one of two states that do not allow self-service at the pump.
I had what happened to you happen to me twice. First time, it was on my '83 Chev G30 w/6.2l (substantially the same injection pump as the ones on our 6.9l Internationals), and I drove it eight miles before it died. Spun the primary filter off on the side of the road, and out came gasoline.
Since I did not dispense the gas, and the fuel door label clearly said, "Diesel Fuel Only", the station's insurance company picked up the tab of towing to a Chev dealer, having the injection pump flushed etc. I got a call saying it was ready to be picked up, I drove it one block and drove it right back: the van was blowing a lot of black smoke, and since we'd had the van since new, I knew what that wasn't normal. Turned out the dealer tried to cheap out and just flush out the gasoline. It ran OK, but lots of smoke, and lower power.
I insisted that they fix the smoke issue, so they replaced all injectors and the injection pump. That took care of all the problems. Cost: about $2300.
Almost exactly one year later I had the same thing happen to my '82 VW Rabbit diesel. That one only made it 2.5 miles before dying, and knew right away what happened. Same scenario with the station's insurance company, and in this case they bought the car from me (totalled it), I bought it back from them for $100 and did my own purge & flush, and it also smoked badly after that.
Moral of these stories: you are going to need to replace the injection pump, period. Possibly also the injectors. The engine itself will be fine, but the injection system is toast. Take it from someone who's been there.