Helmut^ and his girlfriend (deLish* or something) are undeniably ghosting, she even clearly said so once. Most of the talks were audio but I believe some were written so you can check the chat logs (it was 3 or 4 weeks ago, they were CT on dust then continued T on piranesi iirc).

Other than that, when he's alone he's good but I don't believe he's hacking. Most people forget the fact you can often see enemies on your radar if one of your teammates saw them (or died), not to mention team chatter and obvious corner checks.