How should this NPC react?

[Togath]

In a campaign I'm running(Shackled City, converted to PF), one of the npcs aided a group of muggers(or at least what amounted to muggers) in assaulting a young paladin in training.. The PCs managed to catch the thugs without killign them, as well as reform them and get them jobs at the temple.. The NPC that helped them thinks they succeeded, and that the Paladin in training was likely found by a group of guards, battered and nearly dead and carrying a warning for the temple not to interfere with the recent kidnappings..
Would having him saw "I doubt the temple will offer much aid Grandmother*, after what happened to poor Keith**" be too obvious of a reveal that he's involved somehow?
(I'm tempted to just say "The locks!, Look at the fricking Locks!" a this point, as the players have gone off in several different directions, including one who thinks the riddle that's supposed to lead them through the first adventure meant Lochs, such as the one in the center of town, instead of Locks, as in, the things on doors.. which is sort of weird, given that this is play-by-post, so he could see that I spelled it "locks")

*he calls the old woman who raised him and runs the orphanage he works at(which was also the most recent site of the kidnappings) "grandmother"
**Keith is what I decided to name the young priest who was attacked.

[BWR]

OK, if I understand your very muddled and information-poor explanation of things.
Your NPC has aided a bunch of muggers who targeted a P-i-t, but was not in on the actual mugging.
The PCs foiled the attempt, and then reformed the muggers, getting them a job at a temple.
The NPC doesn't know this, but believes the P-i-t was saved by some guards instead.
The NPC believes that the P-i-t was found with a message warning him/the temple to stay away from the kidnappings.

Why haven't the muggers told the PCs about the NPC's involvement?
What was the purpose of the mugging if not to give the P-i-t the message?
Wouldn't the muggers have the message on them?

I honestly don't see how saying "I doubt the temple will offer much aid Grandmother" can tip the PCs off. Would he just come up to them without them knowing him and say something like that? Is he already known to the PCs and are they likely to ask him if the temple would help them?
If not, why would he get involved?
Why would the temple be unwilling to help if one of their own was assaulted?
(Paladins are known for their unflagging cowardice and susceptability to bullying by petty thugs, after all)

If you really have a problem with PCs and players not getting it and going nowhere with the investigation, roll an Intelligence check for them, and hint state that those who make the roll (fudge if necessary) realize that they have been looking at the wrong thing and should look at locks, not lochs.
I've done that when my players are stuck (after letting them explore on their own a bit, of course) and the players appreaciate the fact that their characters are allowed to remember or understand important clues to keep the game moving.

[Telonius]

I've run Shackled City twice (once as a player and once as DM) and that thrice-cursed Locks investigation derailed things both times.

Here's how I'd handle it. Have another breakin, another kidnapping; make a big deal about the fact that there wasn't even any damage done to the locks. If that doesn't clue the characters in to who they're supposed to be investigating, the locksmith himself ought to contact the party, maybe using (can't remember the guy's name - he sells the PCs some information later on) as a contact. The locksmith's gotten desperate with the Dark Creepers coming in and out, and really wants to help out, but is afraid what will happen to his familiar if it's traced back to him.

[Togath]

The players have finally gotten the idea that the locks might be noteworthy, though I did miss the chance to have the orc reveal any plotline..
Now I'm trying to decide how hard I should make it(knowledge check-wise) to know that Ghelve makes most of the locks round town.. I'm tempted to just make it DC 10, since all of the party are natives.