It's entirely possible that Aditya is actually just working on a static analysis tool, it is buggy, and he wasn't aware of the other research his advisor does. If that is the case, I can kind of understand his response. I would be pretty upset if I knew I was just trying to submit some honest(if buggy) patches, but was accused of being a scoundrel because of something that didn't even involve me.

Of course, it's also possible that he is just gaslighting Greg and actually was doing the same kind of "research" as other people did before.

I think that UMN will get to the bottom of it - it will be pretty clear to them what kind of research he was doing, and whether he represented himself honestly.