Well, in hindsight now, I think the answer to that question has become obvious. Sheldon is picking up personally what Pinetree is unloading, so that in a sense is like a cross in order to act independently of one another now as they should.
I really doubt that Sheldon and Pinetree are that independent of each other at this point, given his holdings. He probably refused to pony up for these shares in the context of a private placement, knowing PNP was in a desperate position and had to unload. He knew he'd get them cheaper that way, and he probably used the opportunity to short them on the side to boot. Insider trading without the technicality of being an "insider"...