Omniscient Dumbledore -- smoking gun?

[catjaneway]

No: HPFGUIDX 135256

Betsy Hp:
Again, for me it's a question of degree here. Because Dumbledore is
*so* much more complicit in Snape's case. *Dumbledore* is the one
who brought Snape in. *Dumbledore* is the one who chose to trust
him so completely. <big snip> If Snape really is ESE it means that 
Dumbledore examined that question and came up with the completely 
wrong answer. It would mean, in other words, that Dumbledore is a 
fool. And it would mean, IMO, that any "wisdom" he passed along to 
Harry would be suspect. 

Nora:
This seems to me to be excluding some potential pathos and latitude
here, which is that Dumbledore could have been partly right and
partly wrong in trusting Snape. That is to say, there could have
been reasons good enough for Dumbledore to trust Snape, but given
Dumbledore's canonical personality flaws, he failed to pick up the
lingering resentments and dangers within Snape's personality and
character.

Lupinlore:
It is scarcely surprising that Dumbledore underestimated the depth 
of Snape's feelings, and it is quite plausible that all sorts of 
things might have been going on in Snape's pointy little head that 
nobody knewanything about.

Janeway now:
I wonder if we don't have canon evidence that Dumbledore did
indeed fail to pick up on the "lingering resentments and dangers 
within Snape's personality" – but not because DD was a
fool, but instead because of Snape's skill at Occlumency. (I
posted part of this thought elsewhere, but it seems much clearer to 
me after reading everyone's thoughts in this string.)

At the end of OOP DD admits that he was wrong in thinking that 
Snape "could overcome his feelings about [Harry's]
father," and he calls it an "old man's mistake".
However, we saw in the "Snape's Worst Memory" chapter
that Snape
deliberately removed his memory of James humiliating him before 
teaching Harry Occlumency. Isn't this the smoking gun evidence
that 
Snape has been hiding his true feelings and motives from 
Dumbledore?  

Per Snape, Occlumency depends on being able to "shut down those 
feelings and memories that contradict the lie" (OOP, p531 US HC). To 
me the fact that he removes this particular memory means that it is 
one he especially needs to protect, because it "contradicts the lie" 
that he told to either DD or LV. Normally he is able to "shut down" 
this memory, but as we saw, during an Occlumency lesson one is more 
vulnerable to inadvertent revelations. He didn't want Harry to 
accidentally come across those memories in the course of Occlumency
lessons and report them to DD (or somehow reveal them to LV), so he
removed them completely.

And what does that memory reveal? That Snape hated (and had pretty 
good reason to hate) James. Not just for saving his life, but for a 
sustained pattern of bullying and humiliating him. If Snape has been 
hiding this from Dumbledore all along, it's not so surprising
that DD would be mistaken about Snape's motives. And since Harry
had seen this memory, he had better insight on Snape's true feelings 
than DD did.

Sorry if this was perfectly obvious to everyone else already! I was 
always too focused in on what Snape might have been hiding from LV 
to think that SWM was evidence that Snape was lying to DD.

Janeway

P.S. Annoyingly, I can't seem to get the lines to wrap properly, so 
I apologize for the uneven lines. I hate that! :P