IMPO, this is the most probable explanation for what happened in the following fatal accident:

13/6/00 Ian Swift Hyperoxia Inspiration 41 year old. CNS hit at 43m. Diver tried but failed to bail out before convulsing. Unit had gone back to APD 5 times due to equipment faults.

Unit had no working brown out circuit, no watchdog circuit, handsets were prone to hang. Likely the master handset hung with O2 injector on.

It is a shame on all of us that sites like Diver Mole state his name and the cause as "User Stupidity", when they have not investigated enough exactly what that unit can do.

Alex