I was living in Seattle at the time, home of Boeing. The community was hit hard by the news. One line of thought back then that you haven't explored was that this was an intentional probe, the Chun had deliberately taken KAL 007 off course and that KAL 015 contained monitoring gear to follow what took place.
In my own mind, this took on added credibility when I learned that Senator Henry Scoop Jackson, an anti-Soviet hawk, had been scheduled to have breakfast the following morning with Seattle resident John McCone, Former Director of Central Intelligence under President Kennedy. Unfortunately, shortly after having been informed of the fate of KAL 007, Senator Jackson had a massive heard attack and died. My contact said that McCone's house staff were quite upset the next morning. Jackson was a beloved guest in the McCone household.
Interesting note: I passed that information on to writer Mark Dowie, a Canadian citizen and contributor to the leftist Mother Jones magazine. Several weeks later, my contact, a carpenter who had been doing repairs on McCone's house overlooking Puget Sound, came to me with another piece of information that sounded like an implausible canard being used to confirm an information leak. I ignored it, but that itself suggested that the news of the McCone-Jackson breakfast appointment had floated up in a monitored communication somewhere that got back to McCone, adding valence and interest to the significance of the breakfast that never happened.
Odd times those were.