It appears from the map that the Russian plane was flying across a finger-shaped land peninsula of Turkey, which at that speed would take only 17 seconds to traverse, so I figure it must have been a premeditated trap.
The Turks are ***s, and always have been. Wan*er Erdogan having rigged his re-election by closing down all media and opposition, has the fantasy that he can re-commence the Ottoman Empire with him as the numero uno Sultan, while also enlarging it to him becoming a voice in the EU. Most leaders, like Obama, Merkel, Hollande etc. are naïve clowns, Erdogan is a very dangerous megalomanic.