I'd say it's a misconception is that if the computer loses the transmitter's signal you need to call the dive immediately. I've had my dc lose contact with my transmitter many times. It always reconnects a couple seconds later. It's innocuous enough that I disabled the associated alarm. I'm using a scuapro Galileo, but I ass-u-me there are no features (like the reconnect) which scubapro has but shearwater lacks.
I later changed to a higher voltage battery which has resolved that intermittent disconnect problem.
Yeah, I assume that he meant an unrecoverable failure.
And look, yet another report of a failed WAI link!
As far as I'm concerned, the main advantage of WAI is data logging, for people who like to upload their gas consumption to their logs.