Can seller backout of contract in Az?

[Rick Fonseca]

Here is the situation. A seller wants to sell home and hires a Realtor, Realtor places home in MLS and finds buyer, which of course is represented also by a Realtor. Buyer submitts offer and it gets accepted, now that the transaction is in Escrow seller wants to cancel.

Buyer at this time has given notice to vacate where he is renting and also paid inspection, appraisal and jumped thru hoops to qualify.

Sellers reason is because a relative has told them that they have option to cancel if they do not want to proceed.

What can be done?