Could be a false flag attack? I doubt Ukrainian helicopters can even fly that far.
Nope. This is 80 km from Kharkov. This is entirely in range of Ukrainian helicopters. It SHOULD have been heavily defended between the two: ground AD and airborne AWACS with fighters for an intercept.
And yet...it was not.
Also, this was confirmed by the government of Belgorod.
That said, unless this becomes a regular occurence, this is just an embarrassment. Well, unless the Russians don't have backup oil facilities. I'd expect they would, but, let me be honest, my expectations of all things Russian logistics were higher than what we've seen.