I think you're still not getting it. Sponsored posts aren't part of a chronological feed. They're not associated with any specific content. It's probably not this simple, but it's essentially that every 20 posts a user sees a sponsored post. The posts adjacent to the sponsored post are determined entirely by who the user follows.

For users that don't follow this public figure, the Colgate ads are going to appear somewhere else. If someone takes a screenshot and sends it to Colgate, Twitter will say "hey, it was that user's decision to follow these toxic people."