陷阱or正常？请大佬们指教 --> 被要求签 Affidavit of "Arm's Length Tansaction"

Just signed a contract to buy a SHORT-SALE house, the seller's current mortgage company is "SunTrust Mortgage" which is head-quartered in GA (neigbor of Florida), I am in Dallas and my agent did not experience such a thing before. Does anybody have knowledge or experience on this kind of Affidavit of "Arm's Length Tansaction"? Is this a trap or regular requirement in GA or FL? THANK YOU VERY MUCH!