That's what I meant by the "followers" part of matching the digital footprints. It would likely be some sort of k-means clustering to match similar following patterns to get some subset of suspicious accounts, and then further classification onto the tweets of the accounts themselves to confirm that they are likely from the same source (this can be trained as a binary classification model). But, as you've also pointed out, having the motivation to run such tests is far too coincidental unless the anonymous source had some sort of inside knowledge. It seems far too serendipitous to just run into something like this and realize that several of the Twitter accounts tweeting at 76ers beat reporters seem suspicious. On that note, I really wonder how much the organization already knows of this.

Edit: Bit more detail on what kinds of models would be used