I think the probability of a harmful dump would be much higher from the original DTHs than the attacker. The attacker can't sell all that at once nor at a rapid pace without drawing attention from the exchange he is doing it on. It is also hard for him to sell OTC. This leaves selling small amounts over time to ensure he gets the most value out of it as well as avoid attention. Do you agree with my theory?
If I had a ton of coins I wanted to sell, that's what I'd do. But the question is, how much time do we have? Worst case scenario, the ETC price will crash and then he'll want to panic sell to get what he can. Best case scenario, the ETC price rises, in which case the market will absorb the small amounts he sells over time. I imagine the "hacker" is savvy enough to know how this all works, and will not risk destroying the ETC market. If he's smart, he'll devote his efforts to strengthening and bolstering ETC, as this safeguards his wealth.