I joined to random party in a co-op mission and when we get these hostages to area... mission was not complete.. 

It was on XBOX platform

Name - vpnuvZ

It did not say that we lost a mission or we won it. So we left from it. 

It was a rescue mission, when u need to free all men. Just notify you 

https://xboxclips.co/vpnuvz/2f898694-96cb-4f43-8811-eb901979f0fd  - there is a video, cuz I don't know how to share it.