It is of course very possible that a number of the warrant holders sold enough common shares during the summer well above the current share price and are sitting on the cash to buy the warrants. Those people would not require much of a premium if any to exercise those warrants. And the short position might have a connection to the warrants?

If that is what some people did, either they had balls of iron (in thinking they would not miss a further run-up), or they somehow knew the shares would be pulled down in the fall by PNP's situation and other warrant exercisings. IMO there would be very few people in this latter category, and someone with initials SI (who had insider knowledge until he did no longer did) would have been one such.