If frog just went for a relaxing underground rest while digesting, all should be well. If on the contrary the frog goes into aestivation with a full stomach (does not appears likely in your case) that could be bad. For the future, unless planning to aestivate frog; keeping substrate equal to frog's height allows it to borrow and also permits you to easily monitor frog. Keep temps up, humidity stable, and water in dish clean for next couple weeks. If frog is not out yet, maybe it's time to unbury and check, good luck .