Not that big of an "oops" really! Even if you went 500 calories over your maintenance level, that's only 1/7 a pound of fat. And you said you went about 500 calories over your weight loss calories... so maybe that puts you right around maintenance. So, you didn't lose any weight yesterday... you'll lose 0.14 pounds less this week... not a huge deal as long as it doesn't become a pattern.
Now, if you weigh yourself today or tomorrow, you might see a nasty jump on the scale, due to water retention from all that sodium. But you didn't just undo weeks of work in one night or anything.