can apa unilaterally call it off

I can understand the argument that APA did not get to 50% on Friday - that the provisions in the bidder's statement re deemed acceptance are ineffectual - if you accept for 50 out of 100 shares you are not accepting for 100 shares no matter what the deeming provisions in the docs purport to say blah blah. But if this is wrong what is the position? If the part-acceptors are deemed to have accepted for all their holdings, then the 50% condition was satisfied, and the bidder is contractually bound to pay the acceptors and to extend the bid for 2 weeks under the takeover regs - if so APA does not have the right to simply declare that the bid is over - any accepting shareholder can sue in contract for payment - saving millions of dollars in losses for the institutions and hedge funds. Once a contract has been made, one of the parties is not free unilaterally to call the whole thing off. Any thoughts??