After putting incident on hold, last assigned (and subsequently cleared) Service Queue member groups will be assignees for 'Incident On Hold' and recreated incident tasks. Similarly, if an owner is set for the Incident, both these tasks get it as assignment even if Incident has been reassigned to a queue.
Hold Management functionality has been reviewed.
Pointfix that includes a fix for this issue (in the form of an installer for a revised version of the SD.IncidentManagementSimple project) is available for download in TECH212326.
ServiceDesk 7.5 SP1