Seems to me that prices on stocks subject to this sort of manipulation aren't going to be distributed similarly to those that aren't. I have no idea of what either distribution would look like in practice, but it seems like you ought to be able to make some money by preferentially picking your shorts based on the points at which you'd expect them to differ -- the OP's price-to-earnings ratio being one candidate.

How much money depends on how distinguishable this is from a normal shorting strategy, how common this kind of insider manipulation is, and how much noise there is in the system, though. I wouldn't expect it to be a spectacular win in most cases, just a minor advantage.