Winky & probably typo

[Bente13 at peoplepc.com]

No: HPFGUIDX 24118

I have two questions, which probably (as they're pretty obvious) have 
been debated to death already, but I'm new here, so bear with me if 
you can. 

First, in GoF, after Dumbledore has blasted the fake Moody from 
outside the door and the latter is lying unconscious on the floor 
of 'his' office, Dumbledore sends Minerva McGonagall to fetch 
Snuffles from the pumpkin patch and Snape to the dungeon to get some 
Veritaserum and then to the kitchen to fetch Winky the house elf. 
How, if the fake Moody still looks like Moody, does Dumbledore know 
that there's a connection to Winky? 

Secondly, a little later Dumbledore tells Sirius and Snape that 'time 
is short, and unless the few of us who know the truth do not stand 
united, there is no hope for any of us.' Isn't this the opposite of 
what he ought to be saying? 'Unless we stand united there's no hope 
for any of us', or alternatively, 'If we do not stand united there's 
not hope for any of us'. English is not my native language, so I 
suppose I could be wrong, but I don't think I am.

Bente