2012 LEXUS ES350 Unknown Or Other Problems

I PARKED THE CAR IN MY INDOOR GARAGE (PART OF THE INTERIOR OF MY HOME). SEVERAL HOURS LATER, I BEGAN TO FEEL ILL AND COLLAPSED ON THE FLOOR. I WAS ABLE TO CALL 911 AND AN EMERGENCY CREW RESPONDED TO MY HOME. I WAS UNABLE TO OPEN THE DOOR, BUT THEY WERE ABLE TO GAIN ACCESS. THEY IMMEDIATELY DETERMINED THAT MY HOME WAS FILLED WITH CARBON MONOXIDE AND FOUND THAT THE SOURCE WAS THE CAR IN THE GARAGE. THEY DETERMINED THAT THE CAR'S ENGINE HAD BEEN LEFT ON AND THE BATTERY WAS DEAD. THIS WAS THE RESULT OF ME WALKING AWAY FROM THE CAR, WHICH HAS A "SMART-KEY" IGNITION, WITH THE ENGINE STILL RUNNING. I DID NOT HEAR ANY ALERT FROM THE CAR WARNING ME THAT THE ENGINE WAS RUNNING. THE MEDICS SAID THAT 5 MORE MINUTES IN MY HOME WOULD HAVE BEEN FATAL, AND I WAS RUSHED BY AMBULANCE...