I can't understand the cavalier attitude some have here and elsewhere are taking for the sub being controlled by a damned game controller. I would be interested to see the risk assessment document(s) about such a device.
The aviation industry and 'proper' subs have to adhere to strict protocols. Any backup for the controller available? Has the device been modified in any way? Has the device been stress tested? What various power options are available in case of failure? Has it been tested in case of any water ingress during the preparations for the descent, like climbing in to the sub and maybe dripping water on a wire? How many cycles has the device been through, not submersion cycles but how long has the device been used for? Are there documents available for such a device referring to how many movements it should reasonably be expected to respond to over its life, how many movements has the device been subjected to?
The whole scheme horrifies me. What the hell did the bloke who seemingly shunned industry advice and warnings expect to happen?
The situation angers me so much. This didn't have to happen.
I think the reason so many people are being "cavalier" about the game controller is twofold:
1) It's not uncommon for modified game controllers to be used to control professional equipment; even the military uses them. (LINK) and
2) We know now that this tragedy was not due to controller failure. The implosion was almost certainly caused by a failure of the carbon fiber hull -- and the lack of proper testing to ensure that no weak spots or delamination occurred in it over time (LINK).