The strange thing from the start, in my opinion, was the initial Iran statements that the aircraft crashed due to a technical fault. Such things normally take days to determine; and there is no way that anything can be concluded conclusively immediately; except knowledge of a SAM missile firing towards an aircraft (which the people involved may have not have told the upper levels of the government about). It instantly spoke to someone trying to control the story - and not wait for any results.
The other thing is that the suddenness of the event spoke to bomb or missile as the most likely cause based on prior events, although in theory some catastrophic malfunction could account for it (but, that kind of event is very very rare).
Flight 655 on July 3, 1988 was a tragedy, and people can legitimately debate many things about the following investigation and the results. One thing not debatable is that on July 4, 1988 President Reagan released an official statement that the US had indeed shot down Flight 655 by mistake. https://www.nytimes.com/1988/07/04/worl ... ogin=email
(you will have likely have to create a "free" email log in to see the original NY times page and read the statement).
A full competent investigation will in fact prove a missile hit (all pieces gathered together in a warehouse/hanger and inspected); or something else.
Will Iran admit it which shortens the investigation (and focuses it elsewhere as the US Navy did their investigation), will they conduct a full proper investigation, or whitewash things and limit information during the investigation?
I hope for the best in this.
Time will tell...
Have a great day,