It is a definite possibility but over the past 25 years years I have had the occasional frog sustain an accidental fall without ill effects. Bear in mind though a smaller frog will tolerate a short fall much better than a larger one. Odds are you’d know right away if something was wrong but I would monitor it closely for a while. And most importantly learn from the experience. Keep handling to a bare minimum and always have your enclosure in a safe level place.