I'm not saying you're wrong, I'm saying if you're lying then turns out you don't need proof. If you're going to the lengths of making up a massive story that claims that Apple and Amazon are victims of state-sponsored hacking during manufacturing, then adding on a few fake witnesses and saying it took you 18 months is not that hard.
I've got a story for you. North Korea is software hacking Android phones. I've been working on this for 60 YEARS and I have John Smith plus 70 others who confirm it. The problem is, whenever I talk to Google about it, they have an answer to all of my points. And even worse, I don't actually have any evidence of this happening either! I only have my witnesses (who are all totally real), and my word that I've been working on this for 6 decades.
The details of time and witnesses are so spectacularly unimportant compared to evidence that it doesn't matter.
If it's all true and Bloomberg are correct, then you actually need evidence in some form - hardware in your hand, or software logs, etc. The details of witnesses and time are irrelevant without evidence of something going on.
If the Bloomberg reports are not correct, then the details of witnesses and time are still irrelevant, because that's not the story.
Basically, saying "I've been working on this for a long time, and Bobby agrees with me" isn't proof of anything. It lends some support to it, but it doesn't actually mean anything until something is found.