They let them go to catch a bigger fish...
Also the 10-K has been filed.
The fact that you just got 3 thumbs down in less than 8 minutes tells me that shorts are really, really nervous. The dice have been rolled and tomorrow will be a very bad day for them.
On mid March the stock was trading closer to $70. That was probably the offer price being discussed then.
Considering that the stock was trading around $69 on march 14 and around $30 after that date, then it is no unreasonable to think that the offer was closer to $69.
The same can be said for bears regarding trading prior to the AH news, since we now know so much more about the company, considering a buyout offer was discussed.