[notahacker]

I think you've probably nailed it.

Looking at the mostly-redacted names OP's screenshot I suspect the additional "passengers" Google's email has picked up are actually Dr Axel Schmidt and Oliver Wagner from Germanwings' executive board? Am I right?

[scottmcdot]

Yes you are right! I presumed it was this guy [0]. Nice to have put this to bed.

[0] http://www.neuro.univie.ac.at/