I think it depends on the situation and seriousness of the hit piece. For Citron there was no need to halt but for the MW report it should have been halted the next day.
Management was probably scattered around China for the holidays and were not in a position to respond for some time. The letter we got from the CEO was good but again management was still scattered and they didn't do anything above addressing the bigger points from shorts, and it didn't have a lasting effect.
Now I get your point, the fact that by the time they halt the stock the shorts would be long gone and the damage would be done. But this time its different, we are on RegSHO again and that is a telling sign. We probably have close to 7 million shorts, even more with the puts and they didn't move on. They are intent on causing more damage because they are greedy, spineless, manipulators with no fear of authority or respect for their fellow man.
The stock should be halted, whether the SEC does it pending an investigation on short allegations or CCME requests it. The shorts shouldn't be allowed to leave the party on their terms anymore and CCME should recognize what they have to do and use the money they have to crush the shorts. Its the only way people will respect this stock again.