Disclaimer: I did not see the race yesterday
But regarding driving etiquette in double waved yellow zones, there has to be some responsibility placed on race control to uphold the rules. The drivers have learned that there are little to no consequences to racing at full song through double yellow situtations so they do it (and partially are required to do it).
I am a kart racer and we use local yellows and we are supposed to slow down and be prepared to stop, but there is no enforcement to people who go through at full speed. The drivers learn very young, if they see a yellow and do the reponsible thing (slow down) the guy in front of them does not slow down and they lose a ton of time to the guy in front. If the guy in front gets no penality, guess what the responsible driver does the next time...he blasts through (by competitive necesitity). These are competitive drivers, they need to be held to the rules by race control.
We had a new head starter yesterday, he threw the green flag at anything...guess what, everyone (myself included) was jumping the start because he always gave the green flag and there were no consequences. It is easy to say that drivers should be responsible and respectful of marshalls, but the reality is that they won't if they are not forced to. Because the one guy who is respectful, is the guy who gets left behind.