Best street course IRL race I can remember in a long time. Mild blocking by Sato - I can't believe you aren't allowed one move.
You are allowed one move.
If the guy behind you moves to the inside, you can move down. What you can't do is move back to the outside if he tries to cross you up. Or move down again, if your initial block didn't completely take away the inside, which is what Sato did on Newgarden.
Either way, he didn't deserve to win the race for that chicken ****, so it worked itself out well enough I supposed.
Not sure anyone will care but Kurt Busch tested an Indy car for Andretti at Indianapolis. He said in the future he would like to try and attempt the double.
During the broadcast they made it sound like you could not make a reactionary move - e.g. if guy behind makes a move you cannot THEN make a move. That is different than being allowed one move.
What Sato did was go middle then dive inside when Newgarden tried the inside. It was clearly a defensive reaction move (block) but it was only one move.
In total, he probably violated the rules but it didn't look that horrible to me and compared to other moves you see in other racing it seemed pretty mild.