The UK ambassador to Mexico reportedly left his post earlier this year after he pointed a gun at a local member of embassy staff.A video posted on social media, originally reported by the Financial Times, purports to show Jon Benjamin aiming a rifle at another man while looking down the weapon’s sights.It was captioned: “In [the] context of daily killings in Mexico by drug dealers, he dares to joke.”Mr Benjamin hasn’t commented so far on what appears to have been a badly misplaced joke. No official announcement about Mr Benjamin’s position has been made by the UK Foreign, Commonwealth and…