During the 2021 season, in-race radio communication was often heard where team principals were complaining to Masi about infringements by other teams. This led to the perception by many that Masi was being influenced by teams when making decisions.
During the 2021 British Grand Prix, Lewis Hamilton and Max Verstappen got tangled up on the opening lap, sending Verstappen off the track and into the wall. Hamilton was given a penalty but still won the race.
After the race, Red Bull boss Christian Horner revealed that he had spoken with Masi who advised him to go to the stewards and argue his case, leading to the penalty. Horner insisted he only went to the stewards because he heard Mercedes boss Toto Wolff was already up there.
"So I contacted the race director and he advised me to go to the stewards, or to speak to the stewards directly, which I did," Horner said. "I don't think the stewards should be interfered with. They need to be clear-headed to be able to make those decisions. I went to see the stewards because I'd heard that Toto was up there, presenting a case. You want it to be fair and balanced, and I don't think anybody should be allowed to see the stewards."