To be sure, Ukraine International Airlines Flight 752 departing from Tehran's Imam Khomeini International Airport on the morning of January 8th with 176 passengers and crew on board was shot down by Iranian air defenses, something which the government of the Islamic Republic has admitted, but there just might be considerably more to the story involving cyberwarfare carried out by the US and possibly Israeli governments.
To be sure, the Iranian air defenses were on high alert fearing an American attack in the wake of the US government's assassination of Soleimani on January 3rd followed by a missile strike from Iran directed against two US bases in Iraq. In spite of the tension and the escalation, the Iranian government did not shut down the country's airspace. Civilian passenger flights were still departing and arriving in Tehran, almost certainly an error in judgment on the part of the airport authorities. Inexplicably, civilian aircraft continued to take off and land even after Flight 752 was shot down.
Fifty-seven of the passengers on the flight were Canadians of Iranian descent, leading Prime Minister Justin Trudeau to point the finger both at the Iranian government for its carelessness and also at Washington, observing angrily that the Trump Administration had deliberately and recklessly sought to "escalate tensions" with Iran through an attack near Baghdad Airport, heedless of the impact on travelers and other civilians in the region.
What seems to have been a case of bad judgements and human error does, however, include some elements that have yet to be explained. The Iranian missile operator reportedly experienced considerable "jamming" and the planes transponder switched off and stopped transmitting several minutes before the missiles were launched. There were also problems with the communication network of the air defense command, which may have been related.
The electronic jamming coming from an unknown source meant that the air defense system was placed on manual operation, relying on human intervention to launch. The human role meant that an operator had to make a quick judgment in a pressure situation in which he had only moments to react. The shutdown of the transponder, which would have automatically signaled to the operator and Tor electronics that the plane was civilian, instead automatically indicated that it was hostile. The operator, having been particularly briefed on the possibility of incoming American cruise missiles, then fired.
The two missiles that brought the plane down came from a Russian-made system designated SA-15 by NATO and called Tor by the Russians. Its eight missiles are normally mounted on a tracked vehicle. The system includes both radar to detect and track targets as well as an independent launch system, which includes an Identification Friend or Foe (IFF) system functionality capable of reading call signs and transponder signals to prevent accidents. Given what happened on that morning in Tehran, it is plausible to assume that something or someone deliberately interfered with both the Iranian air defenses and with the transponder on the airplane, possibly as part of an attempt to create an aviation accident that would be attributed to the Iranian government.