How did Fudge/Snape know about Dementors attacking HP in PoA?

[justcarol67]

No: HPFGUIDX 91202

"Partha Mukhopadhyay" wrote:
> Greetings, folks, how go the lives?

Carol:
Wotcher, Partha! All righ'?

<snip>

> My question is this:
> Near the end of PoA, how, if Snape was knocked out when the 
> dementors went after Harry, did he, and/or Fudge know that the 
> dementors had tried to Kiss Harry? 
 <snip>

Carol:
Sorry, no answers, just a similar question: How did Snape in OoP knew
that Harry and Hermione had gone into the forest with Umbridge? He
leaves Umbridge's office (having refused to give her Veritaserum and
correctly interpreted Harry's message about Padfoot) to check on
Sirius and finds him safe in Grimmauld Place. He apparently leaves the
six DA members in the hands of Umbridge and her Inquisitorial squad,
pausing only to tell Crabbe to stop suffocating Neville--a delightful
example of Snape's helping Harry and company without blowing his
cover). The next thing we know that he does is contact the Order at
headquarters (Sirius is no longer alone with Kreacher at this point)
to tell them that Harry has not returned from the forest and must be
trying to get to the DoM. So he sends them to the rescue and tells
Sirius to wait for Dumbledore, who is on his way. Obviously he has
been in contact with Dumbledore as well as the Order, but that doesn't
explain how he knows that Harry et al. are in the forest. Also, how
did Ron, Neville, Ginny, and Luna escape? They were gagged and IIRC
bound and they were guarded by the Inquisitorial Squad. How could they
have recovered their wands (or pulled them out of their pockets) to
cast those hexes on Draco, Millicent, and company?

My theory is that Snape hid himself in the hallway after contacting
Sirius and Dumbledore, saw Umbridge and HH leave the office and
followed them to the forest, waiting for them to return, and then went
back to contact first Dumbledore and then the Order (who must have
been summoned by Sirius after Snape first checked on him). That would
account for his being able to tell them that DD was on his way and
would give him a reason for telling Sirius to stay behind. But if I'm
right that he followed HH and Umbridge to the forest (the only way I
can account for his knowing that) how did Ron and friends escape
without his help?

Carol, who also wonders how Kreacher knew when to injure Buckbeak