My ten pence worth...
the high pressure pump relies on Diesel to lubricate it. Petrol mixed with diesel isn't going to give the same lubrication.
Works Focus Diesel suffered engine failure after someone borrowed it to run an errand, half filled it with petrol, realised his error, then brimmed it with diesel. He managed to drive it 15 miles before it packed in. The workshop report for the damage stated HP pump siezure, snapped timing belt, 4 bent valves, 2 damaged pistons.
Now i don't want to worry you with the above, granted it's more than the amount you've filled with, but that was the worst case scenario which was an unfortunate outcome.
Another way to look at this would be this, if you put accidentally 14L of water into a petrol tank then brimmed it with petrol, would you expect it to run normally?
Personally, i wouldn't risk it.
03 Fiat Punto 1.2 Active, 2003 Vauxhall Vectra SRI 2.2 DTi