I'm by no means an expert, but usually when a web browser makes a request for a resource it includes a referral header which tells the server where it came from

I'm by no means an expert, but usually when a web browser makes a request for a resource it includes a referral header which tells the server where it came from. This header is probably sent both to the initial javascript request and to the tracking pixels it requests to send new info to Google. At a first glance I feel like if you change the tracking id, and the referrals, you may have some success messing with their system. But again, not an expert and I could easily be missing something crucial.