Although Red Bull chief Horner has been on the receiving end of drivers ignoring orders - most famously when Sebastian Vettel defied an instruction to hold station behind Mark Webber at last year's Malaysian GP - he sympathised with Hamilton's plight.
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He reckons that the fact that Mercedes has had a policy of letting its drivers race freely since the start of the campaign - allied to the team's dominance - makes it obvious why Hamilton did not want to move over for Nico Rosberg.
"Inevitably it is very difficult, because you have the objective of the team and the objectives of the drivers," said Horner.
"The interesting thing at Mercedes this year is that because they have such an advantage they have let their drivers race, and they are not under threat in the constructors' championship.
"You can understand Lewis. He is fighting Nico and if he lets him run his fastest strategy, it puts himself under pressure.
"So it is entirely understandable from Lewis' point of view to say 'not today thanks'."
Horner added it did not make sense for Mercedes to suddenly decide to impose orders this far into the season.
"They have let the guys race openly this year, so it is strange when they are racing again to let one run their fastest strategy," he said.
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