The driver can ask for whatever he wants but the team on the pit wall makes the call because they have more data. Hell they can see no one out in Ferraris pit. But they thought (wrongly) they had enough time anyway.
“The simple answer is we got the maths wrong,” said Toto Wolff. “We thought we had a gap which we didn’t have when the safety car came out, and Lewis was behind the safety car and the calculation was simply wrong.
Something about not having GPS at Monaco.