With all the deals they have coming to fruition, they need a +1. If they come to the table with not cash, they'll have to give up a higher percentage of the profits. If they can stand on their own financially, they can cut a better deal.
Also, the $15M had to be in the works some time ago. We were around $3.00 so there was no clear advantage to the ATM. I think Mika and Suresh know what they are doing, know what they need to make the right deals going forward.
I don't think the buyers of $15M worth of shares are shorting and dumping. I think that sort of buyer sees potential and wants in on it. These PP deals ofter have a 4 month no trade rule attached.