Like...as someone else described it..."hurka hurka hurka hurka SPLAT"?
Sometimes they eat too fast and need to rechew it. After food's set in the stomach a bit it's softer and they can chew it up better.
Gross, I know. That's just a dog for ya.
As long as dog is healthy in other ways, active, no diarrhea, etc. it should be fine, but keep an eye on it to make sure it doesn't get worse.