Christian Horner concedes Lewis Hamilton was within the rules unlapping himself in Germany despite it earning him Sebastian Vettel's wrath.
Fighting for the victory in Sunday's German GP, Vettel was unnerved when Hamilton, who was a lap down but behind the Red Bull after his latest pit stop, overtook him to unlap himself.
The German waved angrily at the McLaren driver and later called the move "stupid", saying it lacked "common sense."
His team boss, however, admits Hamilton was within in his rights, although insists it did cost Vettel time.
"If you look at the rules, I don't think that there is anything to say that a car can't unlap itself," said Horner.
"It's frustrating that it cost us a second and it's unfortunate that he didn't unlap himself from Fernando as well.
"If it had cost Fernando a second as well, then it would have negated the disadvantage of being unlapped. But he was entitled to do it.
"We probably dropped about a second when Lewis unlapped himself, which was frustrating. But when you are fighting for hundredths and tenths of a second, that's the way it goes sometimes."