Realistically you wouldnt bother checking gas or electric as A) They'd probably be out by then and b) if they've gotten inside thats the last thing on your mind survival first theres plenty of houses out there so Idisagree with them but the grab bag thats a yes.
Turn off electricity Grab emergency bag Check the gas
You need to check the gas to see if it is leaking. If your house smells like gas you need to shut if off. You also need to shut off your electricity. Protecting you home base from a fire is critical during the zombie attack because you need someplace safe to return. Dont waste time on valuables.