Was I hacked? Does the Apple Mail App on Desktop trigger a Google “signed-in device”?

Several of my personal accounts were hacked by my former employer (files were altered). I confronted them, mentioned the platforms but only sent them evidence of my Google account being hacked knowing that they might try to sweep it under the rug.

They conducted an “internal investigation” and concluded that the Apple Mail on my work device triggered those sign-ins. Besides the fact that their explanation doesn’t explain why my other accounts were hacked, I tested their theory and couldn’t replicate it. I looked it up and some people said that pull requests from Apple Mail don’t trigger logins. Can anyone confirm?

In addition, I did more digging and downloaded my Facebook data and this is what I found. It shows everything including the browser used, which a third-party app is not.

The hacks coincide with both a complaint I submitted to IT about their questionable practices and false allegations (made by IT a week after my complaint) that led to my dismissal.