Really glad you found him, that's great news!
You mentioned that you placed the rocks softly so you know you didn't squish him. Are the rocks sitting on top of the sand? With a jawfish, you definitely want your rocks to be firmly set on the bottom of the tank/glass rather than sitting on top of the sand. If you have any aquascape with rocks stacked on top of each other, the jawfish will likely dig burrows under the rocks at some point and when he does, the rocks will shift and fall over possibly squashing fish/corals/inverts or scratching your glass. I don't know what your tank looks like, how deep the sand is, how high the scape is, etc... but this is something, if possible to do, that you may really want to consider. Search around if you like; things like jawfish, sand sifting gobies, and others will require that the rockwork has a very stable base. I put eggcrate under the sand on my tanks to protect the bottom glass and to give the rocks something to bite into for a firm base. Good luck!