Not really. If you look at the circumstances around this fraud, it's clear that "they are harassing short sellers" would have been just one more grain on the pile of evidence that was willfully ignored as it was going on, or one more legal violation for authorities to look the other way on.
It's not just Wirecard, there are very often media reports of short sellers or whistleblowers being targeted for harassment by companies while they are engaged in ongoing fraud and it rarely makes any difference to broad public perception or regulator action.
The harrasser doesn't have to say they're doing it, though. The victim probably knows who it's from even if it's completely anonymous.
If the harasser thinks you haven't put two and two together yet, they have two options.
1. Quit 2. Be more obvious
1 is what you want, 2 is better evidence in court, win-win.
I was assuming a hypothetical where you can convince them you actually don't know who is doing it. Obviously if they think you do know, the whole thing changes.