Diver one of sixteen to die using high-tech gear

[DRE]

"When the O2 sensor(s) fail and the unit starts mixing the wrong gases, won't the computer readout tell the diver what ppO2 is being mixed? Even if it gives the wrong number shouldn't the diver know if the number is correct or not? I have to believe that the CCR diver isn't on autopilot. He should know these numbers at each given depth."

Correct, you'd assume that the diver is not on autopilot, but some of the cases in which divers died using their unit was that they were not aware of the audible signals the machine gave them of either a hyperoxic or hypoxic mix. So I believe there is a problem with the warning mechanisms of the unit if people fail to hear them.
Secondly, what's the fun of diving when you constantly have to watch your two computer readouts and check 'em against one another - you might as well stay home and watch the weather channel. Furthermore, the placement of the displays in the frontal area of the diver, and also the placement of the counterlungs on the front side, increase the diver's vertical profile, which isn't any smaller than a hogarthian backmount config, but with a lot more stuff in the way of easily clipping off stage bottles, primary and backup lights, reels, liftbags, etc.
Third, the sensors are placed downstream from where gas is added to the loop. This means that if a high dose of O2 is added to the loop, the diver will notice it on his display as he is about the inspire that mix - it only takes 2 to 3 breaths at depth with an excessive ppO2 to tox. That's why the much more expensive units (such as the Cis-Lunar have the sensors placed upstream so that the machine itself can fix the problem before it actually occurs). The reason why the Inspiration has the sensors downstream is because the design was inspired by Navy pure O2 rebreathers, where it didn't matter that the sensors are downstream since pure O2 is constantly being pumped into the loop, adn toxing out isn't an issue because of the much shallower deths these units are used at (the Navy used to allow pure O2 rebreather use upto 60ft, I'm not sure if they still do. Keep in mind however, that Navy combat divers are in extreem physical condition, and they are screened for oxtox susceptibility - none of which is applicable to the average tech diver).