DD not reacting to Hagrid's mention of Sirius?

[Carol]

No: HPFGUIDX 184171

mysterious_one1987 wrote:
> > 
> > In SS/PS, Hagrid turns up at Privet Drive with Harry,  <snip>
Hagrid states that when he went to pick up Harry, he saw Sirius there
and borrowed his motorbike.
> > 
> > Now, the Potters are already dead, and DD knows that a Fidelius
Charm was put in place to protect their whereabouts from LV.
Dumbledore also presumed that Sirius was the SK for the Potters, so it
would follow that Dumbledore thinks, as everyone else does, that
Sirius betrayed the Potters.  So why doesn't he react at all when
Hagrid tells them that he saw Sirius?   <snip> 
> 
Mike responded:
> Because he's Dumbledore. Think back and you'll find that Dumbledore
doesn't usually betray his feelings. <snip>  Secretive is his byword
and that usually includes his emotions and outward appearances.
Besides which, what else is there to react to in this case. As you've
said, Dumbledore had probably already worked out in his mind what had
happened with regards to Sirius. He may not have expected Sirius to
still have been at the Potters to meet Hagrid, but Sirius, the
Potters' betrayer, was most likely fresh on his mind and the mention
of his name would seem more natural than a shock.

Carol adds:
I agree with you. Also, of course, Dumbledore doesn't want to alarm
McGonagall, or worse, Hagrid, who has already made a lot of noise just
by flying in on the motorcycle. The last thing DD wants to do is to
reveal his suspicions at that point, especially since nothing happened
and Harry has been safely delivered.  
> 
mysterious_one1987 wrote:
> >
> > but I do think that JKR would have mentioned SOMETHING, whether it
be a look, a small movement, anything by DD here, as she usually
employs these sorts of small details to hint at something much larger.

Carol responds:
Ah, but she did. Of course, merely mentioning "young Sirius Black" and
his flying motorcycle calls him to our attention, foreshadowing his
appearance in a later book, as Mike said. But look at Dumbledore's
words: "No problems, were there?" (SS Am. ed. 15). Hagrid says no and
DD is satisfied, but the alert reader wonders why DD would suspect
"problems." Clearly, DD anticipated that Black would try to claim
Harry as his godson, but Hagrid, though not suspecting Black's
motives, has his orders and refuses to give him up. DD must wonder why
Black has given/lent (depending on which edition you're reading) the
motorcycle to Hagrid, especially since he anticipates "problems"
related to Black, but he doesn't want to say anything at the moment,
especially since Black isn't making more trouble *yet.* The trouble
comes soon enough, in the form of Black's supposed murder of thirteen
people--really Pettigrew's disappearance and murder of twelve Muggle
bystanders. So DD is right that the SK who betrayed the Potters to LV
will cause more problems. He's just mistaken as to the identity of
that SK.

Carol, who sensed some sort of trouble involving "young Sirius Black"
based on Dumbledore's quiet words