Half of Mercedes' pit crew did not hear the call
Apparently, the mechanics received the message about George Russell's upcoming pit stop too late, as Russell spoke with sports director Ron Meadows on the onboard radio at the same time.
"The radios the pit crew uses only hear one voice at a time. So it's not like a phone call where more than one person can talk at the same time. At the exact moment that Ron called the pit crew for the double pit stop, George also spoke on the radio," explained Allison.
"Half heard George's message and went off, the other half went to Ron's message."
There appears to be a solution to this problem already: "It's important that we program the radios in such a way that an important call like Ron Meadows' is given priority," said Allison.