First off, sorry for your loss. I have the Top Flite Gold edition Cessna 182 ARF as well. Gorgeous plane.
The only thing I see that you did not do was to do a load test on the receiver battery.
I lost a 1/4 scale beauty one day with a full charged 6v battery for the receiver. I too was pissed about my DSM setup that had even been upgraded to DSMX both Tx and Rx. I was ready to kick that damn transmitter across the field.
I went out to retrieve the plane and once I got it back started looking for other culprits. Rx batter fully charged but when placed under a 1.5 amp load voltage dropped to 2.8v. Bad cell in the pack. This happened about 4 minutes into the flight.
Now I run redundant A123 packs for the radio gear.
I found my confidence once again in DSMx and just got back from SEFF, lessons learned, and no lockouts or mishaps. Flew all day and well into the night most days and there was 402 pilots that showed up to fly, play with boats, and run cars all over the grounds. Not to mention all the cell phone, Mi-fi- Wi-Fi, Satellite TV, FPV flyers and all other sorts of electrical noise. Not a single issue the entire week.