Seller "withdraws" counter offer before written deadline - legal?

[Chris Reeves]

Hey folks,

This situation has not happened to me before so I thought I'd ask to see if anyone else has been through this.

1. On August 16 I received a seller's counter offer on a property. The written deadline for acceptance on the counter offer was August 19 (which I presume means any time up until 11:59 pm).
2. In the early afternoon of Friday, August 19 I received a written "withdrawal" of the counter offer from the seller. The withdrawal noted that I had not accepted the counter offer by 2:30 pm central time, and claimed the seller therefore had the right to withdraw (the original counter offer did not mention a time deadline - only the date of August 19).
3. I e-mailed my real estate agent to ask why the seller had withdrawn the offer. She wrote back that he told her he received a "substantially" higher offer and that the very day he attempted to cancel his counter offer to me 9 hours early, he went into contract with another buyer.

When I received the e-mail containing his written withdrawal of the counter I thought "oh well, that's that" and initially thought I had lost the right to accept his counter offer. I did not realize until today, Monday August 22, when I checked the documents again, that the seller's "withdrawal" of his offer to sell his property was not actually a valid withdrawal - that in fact I had all day August 19 to accept his counter.

It seems clear to me now that the seller was eager to send written notice of withdrawal of his counter offer because he had received a better offer and was chomping at the bit hoping I would not accept by midnight August 19.

My question is - is there anything I can do here? Do I have any grounds to demand the seller perform? I'm going to call a real estate attorney in the morning - just wondering if anyone has been through a similar situation.