Nurcahyo Utomo, the lead investigator at Indonesia’s National Transportation Safety Committee, confirmed that a malfunctioning throttle was “one of the factors that we are looking at, but I can’t say at this point that it’s a factor for the crash or there was a problem with it.”
Ok, this is key. Not outspoken, but a Throttle issue is likely or among the suspects. And then it makes sense they need CVR to detect, why crew was not able to control that situation.
A/P acting on Rudder in 737? Y/D is no A/P