Connecting the dots

[snow15145]

Neri:
Aren't you mixing things? It was Dung who was banned from the HH, but
we don't know that he was the eavesdropper.


Snow:

Not really mixing them up just conjoining them. My assumption is that 
Dung was the eavesdropper and that was why he was banned from the 
pub. 

Neri:

DD didn't have any idea that he's going to hear anything important in
the HH, and then he was probably too occupied with Sybil's words to
pay attention to other things. My take is that he found out that there
was an eavesdropper only after the fact. Aberforth caught the
eavesdropper and threw him out, and only later told DD about it, when
the eavesdropper was already long gone. No wonder DD doesn't think
much about his brother's intellect. Alternatively, maybe Aberforth
failed to even tell DD later, and DD only found out that there was an
eavesdropper when Snape supplied him with information about Voldy's
plans.

Snow:

Could very well be a possibility, however Sirius explanation as to 
why Dung is in the Order fits nicely with him being the eavesdropper: 

"How come he's in the Order?" Harry said very quietly.

"He's useful," Sirius muttered. "Knows all the crooks—well, he would, 
seeing as he's one himself. But he's also very loyal to Dumbledore, 
who helped him out of a tight spot once. It pays to have someone like 
Dung around, he hears things we don't." OOP pg 86 U.S.

Dumbledore is not beneath helping someone out of a tight spot 
especially when there's a return for his trouble. Dumbledore 
persuaded Petunia Dursley, grudgingly and all that, in a little 
different way but I think they both got something out of that deal. 
Of course we are not privy at the moment as to what Dumbledore did 
for Petunia any more than we are to what tight spot Dung was in that 
he was helped out of by Dumbledore. Dumbledore is quite gifted with 
the power of persuasion with many to do his bidding such as; angry 
centaurs who released the toad lady unscathed or a betraying house 
elf who needed a bit of nudging to divulge the information about 
Sirius. We are never informed how these events took place but that 
Dumbledore was involved and the situation defused to the benefit of 
Dumbledore's needs. It seems properly fitting that Dumbledore saved 
Dung's hide and made use of him and his talents in a more beneficial 
way. 
We do know that Dumbledore became aware of how much of the prophecy 
was overheard and that the perpetrator was caught and thrown from the 
building so we may assume that Dumbledore was aware of who the 
eavesdropper was as well. I don't think that Dumbledore was aware of 
the circumstances that night because the eavesdropper did manage to 
get away and inform Voldemort of the small portion of the prophecy 
that was overheard but I do believe Dumbledore became aware of who it 
was and how much they actually heard. It could have been Snape that 
informed Dumbledore as you say or it could have came straight from 
the horse's mouth, which may have something to do with that tight 
spot that Dumbledore helped out with if Dung was in over his head 
with Voldemort. The real key in the quote above is the statement that 
Dung hears things we don't. 


Then there is also the ironic fact that Dung was dressed as a witch 
when he eavesdropped on the first DA meeting in the same 
establishment that Dumbledore came to learn of the prophecy:

"Who overheard us?" Harry demanded.
 
"Mundungus, of course," said Sirius, and when they all looked puzzled 
he laughed. "He was the witch under the veil."

"Why was Dung hiding from us?" asked Ron, sounding 
disappointed. "We'd've liked to've seen him."

"He was banned from the Hog's Head twenty years ago," said 
Sirius, "and that barman's got a long memory." OOP pg. 370 U.S.

Sirius states matter of fact to Harry that it was `Mundungus of 
course' as though it could be no one else. Sirius continues that Dung 
had been using the invisibility cloak for spying up until the point 
that Sturgis was arrested and was now using the witch disguise 
instead. It appears that Dung is used often as a listening device, 
could be his best attribute. 

Just my take on the situation

Snow- a recoving thinker going into relapse all the time