My problem with OotP

[flussbiber]

No: HPFGUIDX 69721

Hi
I joined this group recently and I apologise if this has already been 
discussed to death here, but I have a problem with OotP. Not only is 
the timeline completely wrong towards the end (it takes Snape far too 
long to alarm the other members of the Order) but I'm also totally 
baffled by the fact that there is nobody in the ministry when Harry 
and the others get there. Alright, it may be at night and the Death 
Eaters may have killed some people, but why then did Voldemort not 
just pick up the prophecy himself? Nobody would have seen him in the 
deserted ministry. This really doesn't make any sense to me 
whatsoever. Could anybody help me understand?
flussbiber