Another minor thing from my rereading:
What does (or rather, did, i assume he would ask after this when the colleges are all discussing apparition collecting and bleeding logistics) Reicthard think the golds are doing with the dark hounds? I suppose its a similar question to "so what did the colleges think mathilde was up to when she asked about a rider in red":
But i feel like maybe you'd have more questions if it was a regular thing that keeps happening, rather than a (so far) one off. Especially since a one off could be "i want practice killing apparitions, either myself or for my apprentice", theoretically.
I suppose alternatively, "Do those matters just stay delegated beneath reicthard?" and instead its the... Porter equivalent? And/or perhaps the dean and/or battle wizard organizers? Who would be handling the requests to be told of which brights have unwanted doggos chasing them?
The Colleges are secretive by nature, and not revealing things is their default. They assume that the other Colleges are on top of making sure that their members aren't getting up to anything too dodgy, and in turn they expect the same courtesy, because everyone's doing stuff that looks dodgy from the outside. The Brights just point when the Golds ask where the totally not Flesh Hounds are, and the Golds just build when the Brights want an octagonal cage with eight locks made of blackened iron. That's just how intercollegiate relations work.
Whipping out one's tome and dropping it on the table with an audible thud somewhat disrupts that dynamic, not least of which because now they don't have plausible deniability if you really are getting up to something dodgy, but even then Reicthard is raising the point delicately.