That's where the transparency comes in.
In most linux distribution, when you have a crash and the crash reporting is enabled, you can peek into what exactly is going to be sent. If you have smallest of the doubt, you can opt to not send anything. Or opt out of sending anything, ever.
Of course, seeing that the data you submit is used to solve your specific problem, and not disappearing into black hole just to feed some analytics, helps with the motivation to submit.
No need to debug the constantly changing code. Even if your researcher verifies, that a specific release sends only such and such data, the next months release can send something else. The verification would take longer than a month, and given the cadence of releases, would be permanently out of date.