Oh it's all variable. If you run it on pure petrol it'll die within a handful of engine revolutions - the pump DOES need the diesel to lubricate it. It's an engine-driven pump (driven off the timing chain) so there's plenty of push, and if there's nothing lubricating it the internals will fail fairly quickly.
If you've done 200km since (and have topped it up again as you have said) then my gut says you're past the danger point. Don't take that as gospel though, it sometimes grumbles and makes other decidedly nasty noises as well, especially after eating spicy food!