In my experience with escalation clauses, the offer that triggered the escalation clause resulting in your winning bid is generally shared. Since offers are private, generally it is shared among the attorneys (we use them here for closing) but it could also be between brokers.
It sounds to me as though you are in a strong market - and the escalation clause can be a helpful tool to incorporate into the bidding process to give you an edge.
I recommend you speak to you agent about how the trigger can be verified to put your mind at ease.
Just my opinion - hope it is helpful.
And congrats on winning the deal!!