Methods for use in a dispersed storage network (DSN) to retrieve encoded data from memory device of an impaired storage unit. In various embodiments, a computing device of the DSN issues requests to a plurality of storage units, including the impaired storage unit, to recover at least a decode threshold number of encoded data slices of a set of encoded data slices. When the impaired storage unit determines that it is not able to quickly retrieve the requested data slice for provision to the computing device, the impaired storage unit promptly issues a quasi-error response instead. In response to receiving less than the decode threshold number of encoded data slices and a quasi-error response, the computing device determines to issue another slice request(s) to another storage unit(s) and/or issue a continue request instructing the impaired storage unit to continue processing the request to recover the data slice stored therein.