Re: Avionics experts and the court of public opinion....
The reason why we're now seeing groundings is because of how the FAA and Boeing have equivacated over the implications of the Lion Air crash, made worse by the seemingly similar circumstances of the Ethiopian crash. It seems like the FAA have maintained a line of business as usual, nothing to see yet, not even giving out guidance on how pilots should be trained to deal with MCAS, fly without MCAS, etc. It's been a guidance vacuum, other than giving out a note saying "treat it like trim runaway". As I understand it that's not great, because the symptoms aren't the same as trim runaway. The info vacuum is what's finally lead the rest of the world to ground it.
There's anecdotal evidence to suggest that US pilots are now flying MAX on their own rules, having worked out what is necessary to deal with it. Whilst laudable, and no doubt benefitting from the experience of those with militarily test pilot histories, it does have a technical description; it's called 'Making it up for one's self". Which, strictly speaking, isn't allowed.
One of the US airlines has taken upon itself to give its pilots a raw view of the AOA sensors' outputs so that they can form an independent opinion of the operation of MCAS. Again, that's making it up for themselves. It's unofficial, probably not Boeing sanctioned, but probably a life saver.