Even assuming that the inspection period has passed there may be other reasons the buyer MAY BE entitled to their earnest money back. A few that come to mind are having never received a Form 17 seller disclosure, having not received a title report if the title contingency form was used and there is a title issue, the contract not having a proper legal description, and a decline in financing assuming a financing contingency was used. I'm sure there are other situations that are just not coming to me right now. But even assuming one of those conditions is present, that does not absolutely mean that the buyer would be entitled to the earnest money back. You would need to consult an attorney.
Best of luck!
Your contract will indicate this. Without seeing how the offer was written, we really can't say. 3 weeks is beyond most standard contingencies other than the financing contingency. The financing contingency, if they used one will require a good faith effort to obtain financing and generally will require a decline from the lender for a reason.
Your agent/broker should be able to review the offer with you and advise you. If you don't have a broker and this is a FSBO, you'll need to read the contract and consult an attorney.
It depends on the time-frames outlined in the agreement. If the time-frames were adhered to the buyer gets their earnest money returned to them.