I Norway we lost a Widerø Twin Otter in the late 70s or early 80s due to a Harrier.
The problem was it happened way east of the line Norway had drawn for NATO aircraft as a buffer before you hit the Soviet border.
Was all blamed on the Otter crew. Many years later it turned out the Harrier was using it as target and bumped into it.
Same as happened to Gargarin except the Harrier made contact and was damaged.
Intercept of airliners of any kind for training is not allowed to my knowledge anymore.
Why, ask the US Navy P3 that was intercepted and had to land in Hainan some time ago.
Anyway, it was a PLOC , it looks like?