Guess you missed the biggest portion of all that copy and paste you did, noloah...
"..shall render to a person injured in the accident reasonable assistance..."
There are some specifics cited, but there are no limitations to that portion of the code, noloah. In my hypothetical...would it not be reasonable to "direct the traffic" away from the person injured lying in the roadway? If you just stand there and let the injured party from your accident get ran over, what assistance did you reasonably render?
Likewise, if you want to post the code portions concerning impersonating an officer now, go ahead, since that was your initial claim. A simple waive is not acting as an officer and you would be laughed out of court making that claim. Secondly to all of this....there is no code anywhere in Iowa Code that says a driver cannot yield their right of way voluntarily.
A third point is your first senario was 20 years ago when there were even less laws....but I can tell you the Davenport officer was wrong telling you anything like " it's sort of like impersonating an officer" and that waiving through was illegal. "Sort of" is not a violation of anything, Noloh, and there was no law 20 years ago that said that. I was still a certified officer then. BTW...was that other driver cited for anything?
You also posted that the "waiver" in Davenport left the scene of the accident. They had no legal duty to stay, as their vehicle was not involved in the accident. They were morally wrong, but not legally wrong.
I'm just sorry you have been misinformed all these years, but to post "When you direct people through, you are impersonating a peace officer", you are doing a great dis-service to the public via misinformation.