But that's not the same definition as the word he used. Fire/flame retardant basically means "fire delayer" Run that through the original sentence and it becomes nonsensical: "It's totally 'delayed' that a functioning phone is bricked by an update".
In my dictionary it coild also be It's toally backwards that.... Does it make sense now?
Fire retardant example was to show you that the same word can be used in many context and not all of them have anything to do with offendong handicapped people. oh wait that word is now also politically incorrect.