That scene, though, also involves speaking about Balon Greyjoy, if I remember correctly? Cat makes some statements about his trustworthiness, and Ned fighting against him, and whatever else. There's no one else to convey that information, and it does provide a lead-in to Balon's reaction toward Theon's presence for the second episode. In that case, why not hit two birds with one stone in that scene, as opposed to another scene?
That's just some minor devil's advocate, for the record. I don't disagree with the point that the brief mentioning wasn't necessarily needed there, and that it could be a potential misstep.
The overall point you make is definitely spot-on and correct, too: a story needs to fit its medium. When considering an adaptation, the new medium needs to be the first consideration for storytelling. What works in any one medium does not necessarily work in another - the easiest to illustrate, for Game of Thrones, is our losing a lot of what goes on in the characters' heads.
Do you remember any of your examples from the first season? You can PM them to me, if you want, in the event you're wary it'll turn into a ****storm. Or tell me how many pages back they might be, and I'll dig and search. Just curious at looking at some, and it'd give me an excuse to open the packaging, which I haven't done yet.