Even though you had come to agreement on sales prices, the contract was still, basically, contingent until your option period was over. YES, it should have been placed on Active Option, but the seller can request for their agent to still actively advertise the property until the contract actually becomes "PENDING". At that time, the agent is obliged to place the property in that status and stop actively advertising the property as available.
I guess I don't understand what you are asking because in the end, you didn't go through with the purchase anyway. Am I missing something? If you were asking if the seller could have negoiated another offer during this period, NO. They could, however, have taken a "back up" offer in the even that the home purchase did not go through.
Hope this answered your question to some extent.