As is often pointed out, the team radio messages are sent in the heat of the moment, and when the red mist comes down every driver is quite sure they're in the right. Piastri also came across team radio asking WTF Sainz was doing chopping across the apex out of nowhere, when by the strict reading of the rules Sainz did in fact have the right to the racing line. Rules aside, though, it's just poor racecraft to move around unpredictably at race start, and frequently ends with you throwing your race away on the first lap.