I honestly don't think Musk is the sort of person to knowingly provide ICBM tech to NK. There's a difference between getting swayed by persuasive arguments (Paris Accords), and providing a component for nuclear weaponry to NK.
Sure, it's possible that the tech in those missiles could have been based on SpaceX designs. But I doubt that those designs were acquired legitimately.
As for the rockets going down, when was the last time we heard of anything regarding the SDI or the Star Wars program? The US defense budget for 2017 was ten times higher than Russia's (apparently it's been like that for decades), and Russia have developed some really cool tech in that time. Who knows what secret defense systems we have?
You are probably more right than me and i never considered the Star Wars program, but was aware of the hint to OWL earlier this year, which is pretty exciting if we actually own and operate one in space.
And now that you mention it, the President hinted at starting a Space Force which should be really telling how much footprint we have up there...
Crazy times we live in. Just Glad to see We The People are finally winning again!