no it's not. that is just utter bullshit. US is not world police. unless they can prove US citizens were TARGETED specifically than maybeeeeeeeee and that's a maybe. US shareholders can be affected by anything in the world a sneeze and a fart as well doesn't mean that gives US the reach to other jurisdictions.
That's complete conjecture. Do you have any evidence to suggest the US wont be interested in a multimillion dollar scam when US citizens start complaining. You think they will do nothing? There are UK citizens extradicted to the US every year for similar frauds.