30 minutes (even 15 minutes) seems like a REALLY long time for a burglar to be making all kinds of noise attempting to compromise a gun safe instead of grabbing stuff sitting in plain sight...especially for a crime of opportunity.
A reciprocating saw in a closed up home is not going to be heard from outside a well constructed home. I've seen break ins where the thieves stole everything in the open. Went through and emptied every drawer and cabinet in the house and took those items they wanted. And then hooked a chain to the safe to sheer the bolts holding the safe to the wood decking loose. They then loaded the safe into the back of a pickup truck and drove all of this out of a gated community with CCTV cameras. I dont know how long they were in the house, but the actions they undertook didnt indicate they were in a hurry. Some people are smash and grab thieves. Others are content to take their time.