I haven't worked very much with servers but from my guess is the server could have overloaded and crashed on the server computer itself, that 10 to 15 second lag in game might be a cause from a hardware failure on the server PC. I may get a lot of heat for saying this but "cheat engine " from some players i heard of here on the forum a few days ago might have been cause for overloading the server due to its usage. Please if your using it ,stick to client side only at least until the developers find out whats causing the stability issues. Client side at least wont effect the server. Remember this is pre beta not official open beta.
For those who are calling bull , i'm simply giving advice as any Good Tech would do. I'm currently in process of opening my own business for Computers , I'm more than willing to help with technical issues and involving any hardware process of elimination.
and again as i said I'll be more than willing to help with questions. Just PM me or tag me in a thread.