Screaming mostly because Roberto Pietri (back rider) is a world-class racer, highly paid to do this.
God love my man Ray (WellDrilleRR), but he's a club guy who paid highly to do this... Big difference in talent/speed/result. Bottom line Roberto had a lot more on the line than Ray did, so he took it pretty bad.
Getting pissed when you clip a slower rider happens, but when you take it out on that rider, you're simply a dick...