escalation clause in contract how to screen fake offers pls Help?

[Ethan Antwain Reynolds]

Put in an offer for 153k with an escalation clause to 167k and it was escalated to 166k how can I check the legitimacy of the offer that caused the escalation?

[Steve Morris]

If a buyer put an escalation clause in the offer could the seller then counter at the top of the escalation clause whether someone else bid up to that or not?

Sure, the buyer's tipped his hand already which is another reason why I don't like an escalation clause.  You're letting the seller write the buyer's offer.