Thank you all for your replies.
My colleague’s earnest money deposit is $3000 and purchase price is 550K. Now my colleague transfered his down payment and closing cost to escrow account. Seller agent did not agree on paper to waive penalty, because she/he did not get any reply from bank (I believe Deutsche Bank). But she said bank will waive penalty except for two or three days. Already my colleague gave a notice “Notice to seller to perform” to close escrow in 72 hours through his realtor. As per realtor, seller or seller’s agent must respond in 24 hours to the notice.