I understand what the screenshots are saying and this makes it clear that it was a misunderstanding and that NO ONE ACCESSED YOUR GRAPH(S). Please let me explain
Lets start with your first screenshot: https://www.dropbox.com/scl/fi/g9jv8eh1ugi5qda0c6azx/0811202...
If you take a look at this screenshot, it shows that the values you saw are in the indexeddb db "..._help-tx". The "help" bit denotes that those are the actions/txs taken in the "help" graph (which you can access via https://roamresearch.com/#/app/help). The reason you're seeing Bardia and Conor's emails there is because they wrote in the help graph (maybe they were writing guides there or adding stuff to the changelog). The reason the help graph data is in your indexedDB is because you probably opened the help graph at some point.
If someone had accessed your graphs, similar txs would have shown instead in the indexeddb dbs "..._DZ-tx" or "..._programming-with-categories-tx"
Everything I've said above can be verified if you say go to any Roam graph, and see what dbs are stored in IndexedDB in the devtools.
Hopefully this makes sense. Also, as Bardia replied in the email, we have never and will never edit user notes without explicit permission.
tl;dr: You thought you were looking at the logs for your graph but you were looking at the logs for the "help" graph. This is easily verifiable from your screenshots itself if you know where to look (details above).