I will listen to your expertise on this but...
In your experience has race direction/control in any series level never taken a couple of riders aside and said cool it dudes?
YES
But in the cases of which I am aware the issues were witnessed by race control (all cases involved a bit of push and shove at overtakes).
I have never seen them act or speak with rider after someone 'had a whinge' about an act that was not reported by officials etc. That said, I do know that often they have then kept an eye on the 'offending' rider in an unofficial capacity to 'monitor things' shall we say.
Do they need a formal complaint to call a couple of riders in and reiterate what is acceptable on-track comportment?
Club level, what occurred with Yamaha would be fine but when you start getting to National and International level it is becoming a business and as such there is a due process as we have juries etc that can become involved and the failure to adhere to due process can cause issues with the results of the higher legal challenges
Does it infer bias to say we see a storm a brewin' and we will be watching to see if and where it touches down?
Yes, if and where they address a single rider only
they could absolutely have raised the matter at the riders briefing but given that Rossi had already had his press conference by then, it would have been seen as 'pandering to Rossi' (we cannot forget that MM is not the only rider in the paddock who may not like Rossi)
Certainly if Yamaha got in first, RD could have addressed concerns at the riders briefing but we have to look at things in the order in which they occurred and that option was removed from RD's hands by the press conference
I just think that after Rossi's Thursday bile spewage that some form of official statement (published or in private) stating that eyes are watching and gavels will fall may have had some impact on Sunday's events.
Still would have been seen as pandering to Rossi, if not even supporting the accusations.
In a lot of ways however Rossi has done them a favour with HIS action on the track as RD now have a valid case to get involved before the Valencia weekend and make things clear cut as to the rider responsibilities but again, the risk (for RD) is that MM did not break rules and as such, much of what they do will seem to be pandering.
Whilst all the above is my opinion, I may differ from a lot but I think RD did relatively well throughout thus far in the way in which they have handled the entire sideshow. Whilst I may have my own opinions on the penalty the fact that they stressed that MM's actions were not against the rules cannot be stressed enough (even when some choose not to read that part - not directed in your direction)