I gotta agree with you Busaman...
Sete looks like he tried to dive a bit into the corner, but then it also looked like Rossi's cornering ability was off the mark, like he was sliding out a bit due to worn tires (which is what it looked like led to Sete taking the lead in the first place).
I'm glad there wasn't a disqualification, because there really wasn't enough to validate it, though the controversy is there and will remain I'm sure. Should make for a fun bit of drama as the season rolls on though.