Holy carp, you got lucky!
If not for the dilution of topping off the storage tank that already had diesel in it and topping off your rig at half a tank, your post would have said something like "Filled up tank w diesel, truck died, towed to dealer, they want $10k to fix it!"
Even still, I'd take your truck in and pay for a complete diagnostic test. Now.
The fact that you only had a small percentage of gas (or it wouldn't have run, much less up I70 n back)is reassuring, but it could have damaged the injection pump, internal engine damage and damage to the emissions system in the exhaust.
Man I'd almost be tempted to put some more gas in er and make sure it gets fixed properly by the station, wink wink. You most definitely took some life span off or some major components. This is a tough situation.
Also talk to your insurance company, IMO, as this is simply comprehensive case and let them subrogate any issues back to the fuel station. I think that will formalize your record of this event if you have future issues.
