Moral of the story: don't be a dumb ass.
I'm in trouble then...
In fact I did the same thing. Only it was a 1 ton dually diesel pickup.
Realized the brain fart after I'd put 1/2 a tank in....
It purely a PITA to drain that tank, and get it going again though. At least I didn't let any get to the engine. That would have been much worse.
Glad it wasn't a major hiccup with your tractor!