JS on Smart Investor (video interview), page-35

Start with the simplest (ie most likely) possibility.

A whole number of people/brokers/other companies could have been interested in getting more info on BIG, OM report gets commissioned, OM know that they've found something media worthy, someone in the chain decides to place what is actually a very small short trade and thinks they can make some pocket money knowing what they know and knowing there's a good chance it could warrant a 2nd AFR article. Remember there had already been one an article in Nov - the change of auditor could have been the trigger for the OM report.

There's nothing untoward about taking a short punt. Short trades don't drive a price lower, long sellers do.

If someone placed a a short trade because of info they uncovered and having a hunch it'd trigger news, then good on them for smart trading. Nothing untoward.