your snapping turtle is fine...
when my snapping turtle was about 6 inchs long i was feeding it in a 5 gallon bucket and SOME HOW he got out...i was coming up the stairs and see a turtle flying down at me bounching and such...needless to say i felt TERRIBLE and like babied the turtle for weeks but they seriously have a knack for being okay....if hes acting fine and eating...dont worry aboout it...

just my 2 cents