Yes, when a seller is uncooperative and slow to gather/submit the required documentation, this may stall the review process. This sometimes happens when sellers – who know that a short sale can adversely impact their finances – are reluctant to give up their homes. They may have very little motivation to cooperate.
Also, sellers may be required by one of the lenders to make a payment, usually called a “contribution”, at closing to help reduce the lenders losses. Some sellers wait until the last minute and then refuse to make the contribution or think that the buyer will make it for them. When this happens, the short sale is not approved and will not close. The seller has to understand up front that he/she is receiving a financial windfall and a small payment to reduce the lender’s losses is expected.