If they believe an active investigation has been or will be opened, then the parties actively involved may step back. But it also depends whether those ultimately involved are onshore or offshore - reachable or unreachable.
I would also separate the actual parties that have actively attempted to undermine the company, versus traders that are just responding to tips or patterns in the trading volume. High frequency trading is known to cause a cascade of selling just based on momentum, i.e., a chain reaction.
I blame Canada.