the BUK system is equipped with a civilian transponder safety lock which has to be manually disabled before a missile can be fired at an aircraft showing a civilian IFF.
Too fucking right it was deliberate.
The questions (two of) are:
1. Who disabled the safety lock, and on what authority?
2. Who fired the missile, and on what authority?
Neither of which will ever be answered.
Any punitive action taken over this will inevitably be aimed at the wrong party, will only serve to radicalise, and will only beget more death.
Welcome to 21st Century warfare.